In winter, temperatures of -2 deg C are common, and
-10 is not unheard-of. So
that sounds like insulation would be a good idea. I am unlikely to operate
computers in this building - no electricity or comms services as yet, so it
would be expensive. I shall look into elec costs...
Storing things at relatively low temperatures (but preferrably above 0 C)
is OK. But temperature cycling is bad. If insulating the place reduces the
daily temperature variation, that would probably we worthwhile.
OTOH, I haven't bothered to do that in my storage units here in Silicon Valley.
I should put a data logger with temperature and humidity sensors over there.