TSN and CTV are both owned by Bell, so I think they and Rogers could try to go after all Canadian English-language NHL television rights (in partnership with the Toronto Maple Leafs' team-owned channel, Leafs TV).
And if Bell/Rogers /Leafs TV gets the complete Canadian NHL package, either in one joint deal or in separate deals, here's what I can see:
(1) Saturday-night doubleheaders, weekend playoff games (including all weekend playoff games of Canadian-based teams), and the Stanley Cup Finals move to CTV, keeping them on over-the-air TV. Each Canadian-based team would play every Saturday night of the regular-season, and those games would be on the CTV stations in those cities, with the "best" game going to neutral markets. Each Canadian-based team would get about 25 regular-season games regionally or nationally broadcast on CTV.
(2) TSN would continue some national mid-week games and mid-week playoff games, including all mid-week playoff games of Canadian-based teams. Each Canadian-based team might get ten regular-season games nationally broadcast on TSN.
(3) Rogers Sportsnets (except the one serving Metropolitan Toronto) would each regionally carry 32 regular-season games of the local NHL team. Sportsnet Ontario would get just 17 Leafs' games.
(4) In Toronto, Leafs TV would get 15 regular-season Maple Leafs' telecasts.
(5) And finally, each Canadian-based team would get 15 midweek games on local over-the-air TV. Except in Ottawa, these games would likely be on the City TV outlets, while in Ottawa, the CTV-2 outlet would show them.
Under this plan, every game of every Canadian-based NHL team would be broadcast locally in the team's home city. CTV would get the "Hockey Night In Canada" package (which might be re-named "Saturday Hockey Night" if they can't make a deal with the CBC to buy the "HNIC" trademark); local City TV (or in Ottawa, CTV-2) stations would get fifteen midweek games which would likely be far and away the most popular shows on those channels; TSN would continue to be the national cable home of the NHL in Canada and get more playoff games of Canadian-based teams; the various Rogers Sportsnets would (except for Toronto) each get 32 games; Leafs TV in Toronto would continue to carry live Leafs' games (15 of them).
And if more than one Canadian-based team is in an early-round playoff game at the same time? Put the "biggest" one on TSN, while the other game(s) would be shown locally on either Rogers Sportsnets or local over-the-air TV.