We store our tapes at Iron Mountain. I don't know how far your second
site is. Hopefully not in the line of fire of a tornado. Anyway, Iron
Mountain could get the tapes here before you drive back, and forth, from
your offsite location.
They make some fantastic gun safes which are supposed to be rated for some
extreme fire hazards. That may be a market you may be interested in. Hey,
if they later go to Iron Mountain you may be able to pick up a second hand
gun safe. :-)
Knew of a guy who just used 3 layers of fire rated gypsum board, with the
seams all in different spots for his valuables. Never had a fire to
really test this out though.