-22f that's cold. Some MH originally listed as "winter package". I imagine mid to upper are generally better. Many will have basement and tank heaters dual pane windows up to windshield .You might want to include relative ballpark budget and gas or DP and oldest rig you would consider. Some mid level have higher end builds than say same model 25yrs ago. DP with an Aquahot will make a lot of BTUs for the buck fuel wise as well as add a lot of heat in basement when running hard.My AH is adjacent to wet bays with thermostat to basement heater. They are generally on upper end of MHs. As well as "Luxury" top end.
Keeping stuff from freezing in consistent cold may take some extra effort/parts/ insulation/monitoring /work on owners part, a basement of MH may be laid out different than your 5er and need say small electric heaters or light bulb in cold trouble area.
95 Monaco Crown Royale
M11 400hp, 4060 trans.
Aquahot, Generac Guardian7.5k