I guess that all depends on the interoperation of the words legitimately sized 4 season camper.
If you are describing a slide out, solar powered, flat screen equipped rolling house , I'd have to agree.
If one is happy with the 4 industry essentials: full galley , queen bed , usable dinette, and a basic head. I think it could be just doable.
I'm kind of a minimalist . If I want to watch a movie, my lap top is fine . I carry a small 1000 watt Yamaha genny for auxiliary power. No solar panels.
Demand hot water. blue flame or catalytic heat vs. forced air.
LED lighting etc.
Now due to low energy use you only need 1 deep cycle.
I think it is doable in a full size tc.
Funny you mention minimalist, and speak of saving weight, but you'd rather carry a generator instead of solar?
You also mention catalytic heaters. In a good 4-season, thats the last type of heater you want.
A good 4-season is near air tight, but easy to ventilate to allow air exchange (with regards to humidity)
A catalytic heater will do little more than use up your oxygen and dump CO into your air.
Nowhere did I mention anything with regards to fancy amenities.
Quite the opposite, actually. Hell, I dont even include a water heater in the following list, nor do I a shower....
In my mind, a legitimately sized 4-season pickup camper is at minimum, 8' long with a 48" cabover.
Being a 4-season camper Id like to assume that it isnt for the weekend warrior.
This is Expo-Portal afterall, lats try to stretch that trip longer than overnight, shall we?
Ill assume that the camper must support extended trips (as in months) or even full time.
So, with that said, a "legitimately sized 4-season camper" in my mind MUST include the following:
*Fully insulated with insulated windows and roof hatch for emergency egress
*Efficient sealed burn furnace (no buddy heater here)
*Stove for cooking meals
*Fridge for maintaining perishables on the road
*Properly sized fuel (ex: LP) to supply furnace and stove during extended outings
*Enough space for two+ adults to live INSIDE comfortably, without need to "convert" furniture to accommodate uses
*25+ gallons of fresh water
*Pump of some sort
*Sink and grey water tank
*Chemical or permanent toilet, black tank if permanent
*all tanks insulated from exterior to prevent freezing
*Properly sized house bank to supply low voltage power for fridge and lighting
*Properly sized solar bank and controller to maintain house bank