I had to take a deposition in Tahoe yesterday and drove up
the night before so i would not have to get up at 5:00 and
so i could camp at a hot springs I like up there.  It went
down to about 7 degrees....and i forgot to turn my propex
on....but i did have the cat plat heater (the small one) on
full blast.  It ran continuously all night (7 hours).  In
the morning it was 49 degrees in the cabin.  (i had foil
bubble wrap insulation in all windows and the pop top down
with bed folded out as insulation)  Not bad.  I had a single
down comforter and never got cold.  What's more, the battery
light was still green!
steve