Not necessarily, if you have access to a heat pump for instance you could get much more efficient and cheap heating than a mining rig would offer you. You could also be heating your home using natural gas or some other resources costing a lot less than electricity in some markets.

Being able to reuse the heat from mining does make it easier to break even of course, but given how competitive the sector is I doubt that it's enough to offset the costs in most places.

Yes, a heat pump would be better. I was thinking of what most renters have available - baseboards and portable heaters.

Cover the costs, maybe not. Offset, certainly.