Really nice job thinking and articulating this response. I think you’re right that Airbnb is a significant part of our housing problem.

One nit to pick: a portion of short terms rentals are not made to be long term housing. This is because many short term rentals are located deliberately in tourist destinations (you referred to the location issue) and the format of this housing is made to serve visitors (think tiny kitchens in ski chalets or distance from markets, work opportunities, etc.). It is difficult to say how many of these short term rentals could actually be used for long term housing. I would speculate many STRs ARE actually taking away housing from locals, but your numbers will be lower when taking this into account.

I favor the use of zoning to designate some areas or buildings as STR-appropriate in places that are unlikely to serve locals but otherwise making STRs illegal everywhere else. I don’t know how much of our housing crises this would solve but then we would truly know how much housing Vermont lacks.

This will vary dramatically on the model. Most run at 100% efficiency down to around 20f. Cold-climate models will maintain their cost efficiency compared to oil, LNG, or LP to below 0f and operate below -20f when needed.

Is your Mitsubishi a cold-climate model? It should create plenty of heat down to -15 if sized appropriately for the heating load.