You’re truly never in 2wd with these things. The terrain management system spreads torque based on demand. The terrain selector allows you to decide how it will respond. In normal mode, it is pretty capable in all environments. Sand mode is the most fun because it’ll let you spin the tires a little. Only when it’s really snowy out do I ever mess with the selector. I average about 21.5 - 22.5 highway, but, I have noticed the wind really affects mileage. Likewise, you can never really have it ‘4wd’. I find that pretty handy because you won’t forget about it and kill your mileage or components.
Enjoy the ride. They are a great vehicle!