I was in your situation for the last year. Looking for something light yet something I could take off road and still hunt with in the fall/early winter. Ended up with a StarCraft AR-One with the Extreme package. Just picked it up in the spring so have yet to experience cold weather but that will be tested here in a few months.
I will say that the furnace heats the trailer up quite quickly as my wife made me turn it on when we took a few of the grandbabies camping a month or so ago. The night time temps only got into the 40's or so and she didn't want the little ones getting cold.
StarCraft has a few different floor plans, including hybrids, for the AR-One line. We went with the 18QB as we really wanted a bed that you can get in and out of without having to crawl over each other. Dry weight is about 3200 lbs but it does have small tanks. Plenty of storage for our needs. I could do without the microwave and A/C myself as I bought it for dry camping.
Look up the Extreme package on the StarCraft. What really attracted me was the flipped axle and the existing insulation is wrapped in one of those "space blankets". Oh, along with the sealed underbelly. The tanks are not heated nor inside the trailer but they are sealed by the underbelly.
Come hunting time I won't have any water in the fresh water tank. I'll already have the trailer winterized. I will have a few water jugs for use and keep a milk jug filled with water next to the toilet. Keep in mind that temps here in CO can stay below freezing come the fall in higher elevations where we tend to hunt.
Sorry for the long reply. I plan on doing a review after hunting is over, which will be sometime in Dec/Jan as I've got late season antelope and elk tags.