We haven’t had 3 month rounds in years, but I think you’re right about length being an issue; even our normal 6 week rounds can be a bit much depending on how they play out.
Another solution would be for winning conditions, something @The_LiGhTgUnS has brought up a few times. That way when there’s a clear winner, everybody can collectively move onto a rematch instead of having to sit idle and/or get bashed.