The playing season has to be declared before the start of the season. You can't extend past the end of the declared season except for (i) conference championship games, (ii) bowl games, and (iii) playoff games.

Bylaw 18.7.2.2 limits teams to only one bowl game in a single academic year.

There's a separate bylaw in Section 17 that limits a player to participating in a single bowl game in an academic year (prevents someone from playing in an early bowl game, entering the transfer portal, and then playing in a later bowl game for a new team).