You should be fine with your XLT. I swapped out for tow mirrors on my 10 XLT and everything worked (not sure about heat since I live in FL). When I traded the 10 in for an 11 I re-used the same mirrors, plug and play.

 

So originally your truck didn't have signals on the mirrors, you added upgraded mirrors and the signals on them worked? Or did your original mirrors have signals already?

How about puddle lamps?

 

delete my post

 

My truck did have signals (both 10 and 11) but no puddle lamps. The new mirrors have puddle lamps and they work correctly with no added wiring, just plugged them in. I am just short of 100% sure they will work, the wiring is there and the options are on the mirrors themselves. It makes things easier for the factory to not have 500 different wiring harnesses for each option. I would be very suprised if they did not work, maybe a XL but not a XLT.