As an Arctic Fox owner (better put, as a husband of an Arctic owner) I don't see where an Arctic Fox would be that much better than a normal RV. Yes, better insulation and water tanks protected more etc. But the temps you are talking about it's not going to make that big of difference. Sort of like having 2 sweat shirts instead of one.
Many posts here about what people have done to get more protection in cold weather.
I've seen more than once a U-Haul pulling a TT down the road. Don't know what hitch they have or the details but might be worth checking out.
And in all RV's no matter the brand... I would never buy new again. To much money for what you get IMO.