Are pop up truck campers warm enough in the winter??

Pop up is going to be tough. You want more of a barrier other than canvas separating yourself from wind and snow. Would look for an actual used bed camper or at least a shell.

insulate your windows/gaps, buy a heater buddy (propane heater), a carbon monoxide detector and hold on to ur buttz. I’ve done a week in snow living out of my shell pretty easily but doubt I could last a season willingly. Hardest part was keeping everything dry.

SnowshoeThompsonHardest part was keeping everything dry.

This. Nothing sucks like waking up to freezing rain from your own breath. Four Wheel Campers makes some crazy light, super cool models, but they're hard to find used and a little pricey. Just saw on their website they have a video on winter camping in one of their campers. A pop up with a vent/heater would be alot better than a cap, but I like the cap for how stealthy it is.