If Sinclair were to get taken off AT&T/DirecTV before Nexstar and Northwest stations return, there would be few unscathed markets, with most of those being top 20 or bottom 40 markets (some very small markets don't have local channels through DirecTV). I decided to make this a separate thread than the general programming dispute thread due to the major ramifications.
Markets that would be unaffected completely
Anchorage, Atlanta, Bangor, Bend, Biloxi/Gulfport, Boston/Manchester, Bowling Green, Casper/Riverton, Charlotte, Charlottesville, Cheyenne/Scottsbluff, Chicago, Cleveland/Akron/Canton, Columbus/Tupelo/West Point, Dallas/Fort Worth, Denver, Detroit, Duluth/Superior, Fairbanks, Fargo/Valley City, Fort Myers/Naples, Great Falls, Harrisonburg, Helena, Houston, Jacksonville, Jonesboro, Juneau, Kansas City, Lafayette IN, Lake Charles, Laredo, Lima, Los Angeles, Louisville, Mankato, Meridian, Miami/Fort Lauderdale, Monterey/Salinas, Montgomery/Selma, New Orleans, New York, Orlando/Daytona Beach/Melbourne, Palm Springs, Parkersburg, Philadelphia, Presque Isle, Rochester/Mason City/Austin, Sacramento/Stockton/Modesto, Saint Joseph, Salisbury/Ocean City, San Diego, Santa Barbara/Santa Maria/San Luis Obispo, Sherman/Ada, Tucson/Sierra Vista, Twin Falls, Victoria, Wausau/Rhinelander, Wilmington
Markets affected by OOM default affiliates (i.e. a market that doesn't have its own NBC but the default NBC is owned by Sinclair, Nexstar, or Northwest)
Alpena (NBC), Glendive (ABC/FOX), Zanesville (ABC/CW/FOX/MNT)
Markets that would only lose (or have only lost) a CW or MNT affiliate
Indianapolis (CW/MNT), Milwaukee (CW/MNT), Minneapolis/Saint Paul (CW), Phoenix/Prescott (CW), San Francisco (MNT)
Markets that would lose both CBS and FOX (important as they hold the NFL rights)
Albany/Schenectady/Troy, Albuquerque-Santa Fe, Bakersfield, Beaumont/Port Arthur, Buffalo, Cedar Rapids/Waterloo/Iowa City/Dubuque, Champaign/Springfield/Decatur, Charleston WV/Huntington, El Paso/Las Cruces, Eureka, Fresno/Visalia, Grand Junction/Montrose, Green Bay/Appleton, Greenville/New Bern/Washington, Greenwood/Greenville, Johnstown/Altoona/State College, Medford/Klamath Falls, Peoria/Bloomington, Portland/Auburn, Providence/New Bedford, Rochester NY, South Bend/Elkhart, Springfield MO, Syracuse, Tri-Cities TN/VA, Wheeling/Steubenville, Wilkes-Barre/Scranton, Yakima/Pasco/Richland/Kennewick, Youngstown [Spokane would be missing FOX and one of its two CBS affiliates, but its primary CBS is unaffected]
Markets that would only have one Big Four station
Abilene/Sweetwater (FOX), Albany/Schenectady/Troy (NBC), Amarillo (CBS), Bakersfield (ABC), Binghamton (CBS), Champaign/Springfield/Decatur (NBC), Charleston SC (CBS), Charleston WV/Huntington (NBC), Columbus OH (CBS), Dayton (CBS), El Paso/Las Cruces (ABC), Fresno/Visalia (ABC), Greenville/New Bern/Washington (NBC), Little Rock/Pine Bluff (CBS), Mobile/Pensacola/Fort Walton Beach (FOX), Providence/New Bedford (ABC), Rochester NY (NBC), San Angelo (FOX), Topeka (CBS), Wilkes-Barre/Scranton (ABC), Youngstown (NBC) [Grand Rapids/Kalamazoo/Battle Creek loses three Big Four stations, but still has ABC (the GR market has two ABC affiliates) and FOX]
Markets that would have none of their Big Four, but would still have CW, MNT, and/or an independent
Johnstown/Altoona/State College (CW/MNT), Tri-Cities TN/VA (indie WKPT)
Markets that would have zero non-PBS locals
Eureka, Greenwood/Greenville (no CW or MNT in the market), Syracuse, Wheeling/Steubenville (no CW in the market)
Markets that would be unaffected completely
Anchorage, Atlanta, Bangor, Bend, Biloxi/Gulfport, Boston/Manchester, Bowling Green, Casper/Riverton, Charlotte, Charlottesville, Cheyenne/Scottsbluff, Chicago, Cleveland/Akron/Canton, Columbus/Tupelo/West Point, Dallas/Fort Worth, Denver, Detroit, Duluth/Superior, Fairbanks, Fargo/Valley City, Fort Myers/Naples, Great Falls, Harrisonburg, Helena, Houston, Jacksonville, Jonesboro, Juneau, Kansas City, Lafayette IN, Lake Charles, Laredo, Lima, Los Angeles, Louisville, Mankato, Meridian, Miami/Fort Lauderdale, Monterey/Salinas, Montgomery/Selma, New Orleans, New York, Orlando/Daytona Beach/Melbourne, Palm Springs, Parkersburg, Philadelphia, Presque Isle, Rochester/Mason City/Austin, Sacramento/Stockton/Modesto, Saint Joseph, Salisbury/Ocean City, San Diego, Santa Barbara/Santa Maria/San Luis Obispo, Sherman/Ada, Tucson/Sierra Vista, Twin Falls, Victoria, Wausau/Rhinelander, Wilmington
Markets affected by OOM default affiliates (i.e. a market that doesn't have its own NBC but the default NBC is owned by Sinclair, Nexstar, or Northwest)
Alpena (NBC), Glendive (ABC/FOX), Zanesville (ABC/CW/FOX/MNT)
Markets that would only lose (or have only lost) a CW or MNT affiliate
Indianapolis (CW/MNT), Milwaukee (CW/MNT), Minneapolis/Saint Paul (CW), Phoenix/Prescott (CW), San Francisco (MNT)
Markets that would lose both CBS and FOX (important as they hold the NFL rights)
Albany/Schenectady/Troy, Albuquerque-Santa Fe, Bakersfield, Beaumont/Port Arthur, Buffalo, Cedar Rapids/Waterloo/Iowa City/Dubuque, Champaign/Springfield/Decatur, Charleston WV/Huntington, El Paso/Las Cruces, Eureka, Fresno/Visalia, Grand Junction/Montrose, Green Bay/Appleton, Greenville/New Bern/Washington, Greenwood/Greenville, Johnstown/Altoona/State College, Medford/Klamath Falls, Peoria/Bloomington, Portland/Auburn, Providence/New Bedford, Rochester NY, South Bend/Elkhart, Springfield MO, Syracuse, Tri-Cities TN/VA, Wheeling/Steubenville, Wilkes-Barre/Scranton, Yakima/Pasco/Richland/Kennewick, Youngstown [Spokane would be missing FOX and one of its two CBS affiliates, but its primary CBS is unaffected]
Markets that would only have one Big Four station
Abilene/Sweetwater (FOX), Albany/Schenectady/Troy (NBC), Amarillo (CBS), Bakersfield (ABC), Binghamton (CBS), Champaign/Springfield/Decatur (NBC), Charleston SC (CBS), Charleston WV/Huntington (NBC), Columbus OH (CBS), Dayton (CBS), El Paso/Las Cruces (ABC), Fresno/Visalia (ABC), Greenville/New Bern/Washington (NBC), Little Rock/Pine Bluff (CBS), Mobile/Pensacola/Fort Walton Beach (FOX), Providence/New Bedford (ABC), Rochester NY (NBC), San Angelo (FOX), Topeka (CBS), Wilkes-Barre/Scranton (ABC), Youngstown (NBC) [Grand Rapids/Kalamazoo/Battle Creek loses three Big Four stations, but still has ABC (the GR market has two ABC affiliates) and FOX]
Markets that would have none of their Big Four, but would still have CW, MNT, and/or an independent
Johnstown/Altoona/State College (CW/MNT), Tri-Cities TN/VA (indie WKPT)
Markets that would have zero non-PBS locals
Eureka, Greenwood/Greenville (no CW or MNT in the market), Syracuse, Wheeling/Steubenville (no CW in the market)