Right now, the only thing I can suggest (& you may already know this) is: In southern Milwaukee, try for WGTD Kenosha (91.1), in western Milwaukee, try for WERN Madison (88.7), in the north, try for WPNE Green Bay (89.3). These are heck-of-a-rimshots, but that's all there is right now.
Also, WHAD carries the 24/7 classical music feed (minus all the news & talk shows WPR's News & Classical Music Network offers) on their HD-2 signal. This feed matches WERN's local programming whenever they have local (Madison) classical programs, including The Bethoven Network's overnight hours.