When it comes to using energy I have to say I am tighter than a ducks a*se !!
"Millie" is parked up on SORN from Oct. 31st normally through until at least March at the very earliest but normally May 1st during which time, for most of the time I don't even go into her, however the 3 x MPK skylights I have fitted despite being closed, they still have vents added to which spray foam insulation is incredibly efficient and with zero cold spots to worry about......... as such whenever I do go into her, she smells as fresh as fresh can be.
As the above is the case, I for one don't see any need to leave any kind of automated heating device turned on, but of course, each to their own.
Phil