I mean league champions, not B3 champion. In week you suggested is not known world wide in every single country who is qualified.
Isn't everything finished by the Sunday? If so, any qualifying games can happen immediately following the off-season processing. Then start the tournament the week after.
It might mean that qualifying games happen the same week as the B3 final. But if both teams in the final get a spot, then the issue is solved.
Run of the Mill Canadian Manager