Hi there,
Yeah pretty rural... I did consider the costs and guests not caring about how much they use. This is why we would need them app driven and with 24/7 programming, so we/them could have more control of the usage.
Something like these we've seen online - https://www.electricradiatorshop.co.uk/electric-radiators/radiators-by-brand/digi-line-radiators
It's pretty well insulated now and even though gas/oil would be the logical choice, we like the idea of electric radiators. No pipes fitted and each radiator can be controlled per room.
I guess we need to use a BTU calculator on the rooms first to see what output we'd need and see if it's even doable.
Cheers