If you want a true 4 season truck camper, get a Arctic Fox, not a Palomino. A popup TC won't be easy to heat in cold weather.
SIL and her husband have one and live in Eastern Washington, at the foot of the Cascades. They often camp in the teens.
Dan-Retired California Firefighter/EMT
and Zoe the Wonder Dog(R.I.P.)
2016 PrimeTime TracerAIR 255, pushing a 2014 Ford F150 SCREW XTR 4x4 3.5 Ecoboost w/Max Tow Package