Hello and Welcome!!!
It is probably typical for most trailers, and most are not "rated" for cold weather operation at all, there is no "official" rating system for that. Those that claim so will have it splashed all over their advertising (like Arctic Fox does). The most you can say is that most are made for summer or 2-3 season use, or for southern latitudes during the late fall, winter, and early spring. The best you can hope for is some insulation on the underside, the walls are not thick (2" maybe?) and with single pane glass, probably quite leaky.
You can arrange skirting around the underside which keeps the wind out and which might help a bit with floor and tank insulation. You will need to assure yourself that the furnace air will heat the plumbing and storage area a bit. You will not likely be able to leave the trailer overnight without draining or blowing out the plumbing, depending where it is located and what temperatures you are likely to encounter. Unless you have access to 120V electric there is not a lot you can do to prevent freezing up. If you have an appropriate generator, you should be able to charge the batteries and perhaps direct a small electric space heater or even hang a 60-90W light bulb into critical areas like storage bays or install tank heating pads if the trailer does not have that option installed. Take lots of blankets!!!
When the temps hit 32? overnight in South Florida a couple of years ago and power failures were rampant, we were lucky to make 1 overnight using the furnace and a bank of 2 batteries as running the furnace is very hard on them. (Our 42K BTU furnace runs on 12V + propane as do all RV furnaces)