For instance:At 0°F, a 36,000 BTU heat pump might still deliver close to its full capacity, around 37,000 BTUs.At -4°F, the capacity might decrease slightly to about 35,800 BTUs.At -13°F, the capacity could further drop to around 32,000 BTUs.At -22°F, you might only get about 28,000 BTUs.This reduction in capacity occurs because, as the outdoor temperature decreases, the heat pump has to work harder to extract heat from the air, which becomes more challenging as it gets colder.

They apply, but you are just subject to gift tax at that point, which does not actually result in a tax bill for you, but a reduction in your total giftable allowance which is ~13M dollars. 

While vacation rentals aren't a huge drop in the home supply bucket, they're not nothing, and any reduction in home supply for primary residences will eventually push prices up.

Future Cashflow (rate reduction)

For some lenders, a 3 year prepay is neutral on the rate as as factor and a 5 year prepay is a 1/2 point reduction, a 4 year prepay is a .25 reduction and a 2 year prepay is a .25 add to the rate and a 1 year prepay is a .5 add to the rate.

However, HUD will allow for a reduction in the offer if a problem that's unknown now crops up after the offer has been accepted - I know several people (including my mother) that got some money off their HUD deal.

It had a high # of days on market and a recent price reduction that triggered us to take a deeper look.

There would be closing costs involved, so as @Ray Hage mentioned, a price reduction may suit you better.

So, if interest rates are a buyer’s primary roadblock, then I recommend negotiating a rate buydown at a seller’s expense or looking at new construction, where builders are offering rate reductions and other substantial incentives.What if I’m a seller?

Note even an additional 20% price reduction would not compensate in costs for the increased HOA costs.