Congratulations! How exciting!
Is yours a standard or a deluxe? Front bath or bunks?
There is some uncertainty about whether the wood interior makes it heavier, but the bathroom definitely does because of the extra components. The bathroom will likely put you a bit over the Subaru's tongue
weight rating of 200 pounds. Regardless of configuration you should be fine on total
weight, especially since you will be traveling fairly lightly on this trip.
Quite a few people on the forum tow 13' Scamps with Outbacks. I suspect you'll find it performs adequately except on steep grades, high elevations, and/or stiff headwinds. I agree that having the electric
brakes set up with a controller and wiring in your vehicle is important.
As to weather, you just never know. As long as you don't put water into the plumbing, you don't have to worry about freezing. If you ordered the
furnace, you can use it, or buy yourself a small ceramic electric heater to use when plugged in*. And if a nasty storm rolls through, you can always hunker down in the trailer or even a motel for a day or two until the conditions improve.
*The furnace is a bit strong for such a small space, and noisy to boot. We just run ours in the evening to knock the chill off while changing and again in the morning. You'll want to add your own smoke and CO detectors. For conditions requiring continuous heat all night, I'd look for a spot with electricity and run the ceramic heater instead.
It's the first of many adventures!