What'll happen if I add another Season to Dragon Heist?

We're playing Dragon Heist: Summer, but things have changed and I need elements from another season in there.   It's Summer, and I imported the "Summer" add-on to the game.  However, the players have allied with the Casselanters, so using the Summer chase from Chapter 4 doesn't make any sense now.   I need to change up the chase entirely, with a different villain behind it. Either Zhentarim (Winter) or Xanathar (Spring) would be my preference right now.    If I import one of those into my Summer game, what'll happen?  Will I have access to both? What are the downsides?   Is there a better way to accomplish this?  

If you add another season, it'll simply create a folder kit for the new season with all the content/handouts/npcs, plus add the maps for that season. The map pages are named with the season -- Theatre (Autumn) vs Theatre (Spring) -- so you know which is which. You could dry-run what you'll experience by creating a "new" game and loading it up with the extra season. Whether it's more convenient to copy over a few items to your existing campaign will depend on what you intend to use.

Thanks, Chris.  I tested with a new game and that works as you described.