You obviously take great care of your car! That is the entire reason you would propose renting a car vs taking your X!! Haha. I totally understand where you are coming from with this decision.
In my opinion, take the X!! You bought the car to use it, so use it. You have all the appropriate equipment (all wheel drive and winter tires) for if you run into weather. It sounds like your X is in excellent repair and wont let you down on a road trip.
Take it, love and enjoy the trip in your X. I remember when you bought it and talked about how much you enjoyed the road trip driving it back to CA! Just thought I would throw that in to remind you of how fun the X's are on the road!!
Happy holidays and safe travels, X or no X!