Get offers from a few of the usual suspects to see if you’re upside down or not.
You might not be able to actually sell it to Carvana or Vroom etc. but this will at least give you an idea of how much positive or negative equity you have.
If you’re positive or at least break even then you can shop it to BMW dealers to see if they can match or at least get close. Take any equity and walk away and buy/lease something else.
If you’re negative then it’s really up to you on how much you’re willing to eat in order to get out of this lease. A good set of snow tires will go a long way.