We had a red K 2500 single cab long bed for 13 years and traveled all over western Canada, the Yukon and Alaska in it.
We specifically chose the regular cab so we could have the full 8 foot long bed for our overhead camper and still maintain the shortest wheelbase possible.
We did take out the rear window of the truck and crafted and installed a waterproof “boot” between the cab and the front of the camper. That allowed us to go back-and-forth between the cab and the camper without going outside.
We built a storage tray in the front of the camper, right up next to the boot, for easy storage of ready to grab gear like our cameras, spotting scopes and binoculars, etc. That was pretty useful since the single cab had such limited room for gear up front.