Short bed campers are few and far between. Sharing a camper with your brother? Not likely a good idea. The overhang could cause serious handling issues. A 2500 truck is going to be pretty short on load carrying capacity once you subtract your boats hitch weight. There are such a thing as extended hitches, but, again, not the smartest idea as they really can place a lot of strain on your hitch platform.
As for a camper you can use in cold weather? Again, your probably lacking a lot of capacity with a 2500. If you really wanted a decent camper capable to work in cold weather plus tow your boat, you probably will want to consider trading for a long bed dually. At least then you would have a fighting chance.
Look at Host and Arctic Fox campers, look st their weights and compare thst with your trucks camper load carrying capacity.
