Though I've had the WK2 since September, this past week we took our first real road trip...we have a place up in Vermont and packed up all our stuff, the dogs and left on Sunday morning.
I have the Hemi, and there was never a question that I would get it as I had it in my 06 WK and loved it. It performed flawlessly on the interstate, lots of hills and it did great. It never was at a loss of power. The road to our condo has a very steep hill; my 07 Volvo XC90 V8 would struggle at the top, no problem for the Hemi. I averaged about 17mpg for the entire trip, about 800 miles total, including highway at 75-80mpg and a lot of slow driving in and around town during serious snow fall.
Regarding performance in the snow, I have the stock tires and had no issues...drove through a lot of snow (roads weren't plowed one morning and there was at least 6" down, more in drifts) and never felt concerned that I would have any problems.
The Volvo had great seats, and I was a bit nervous that the GC wouldn't live up to them...actually, they were better. 5 hours going and coming, my back never bothered me, and it always used to in the Volvo. We were very comfortable. All of us.
She knows she's not supposed to be in the front...what else is new!!!