Hi Michelle - I would recommend adjusting the water set-up. I had some challenges with the outside water tank freezing, so with Reace we worked out a plan for a secondary tank inside and put it in the rear of the trailer (under what is now a permanent bed).
Other than that, a bit thicker insulation is all I would recommend. The furnace actually worked well to keep the trailer live-able during -26C.
You'll love the trailer - it tows fabulously in snow (when you get it bring it up to Red in Rossland - you can park it next to mine).