Your best bet to keeping your home heated during the winter months is to set your comfort level temperature and leave it at that.
While it’s unlikely this trade-off is a perfect 1:1, the real question you need to ask is: are we upgrading, or downsizing? One of those will impact your negotiation options, while the other may cost you even more as a result of timing.
Put it this way: photos of you and the fam aren’t going to help the sale of your home.
The better the mortgage rates, the more potential buyers you may have not only locking into those numbers, but also shopping for your home.