I would go the gig bag route. And Uber.
I'll just say that I've toured extensively with gear in an un-climate controlled trailer or truck, from way below zero to above 115°F. Alembic, Guild, David King, etc. Never had a problem. I also let the instrument adjust to the indoor climate (although some of the gigs were in the extremely hot outdoors), but not much longer than it took get the gear loaded in and stage set up.
Oh yeah, any instrument that goes to a gig is covered by Heritage Musical Insurance and they will cover instruments left in locked cars.
