I would have no problem with this decision as I make it all the time when taking long trips. A BMW is not that bad on gas and it is an infinitely better cross country driver. It’s a no brainer…both of your cars are trip ready…take the BMW. If anyone suggests you drive a Civic cross country instead, have them do it or you.
BTW, how does battery weight over the rear wheels of a fwd, improve traction ? ;=)