OK, for a C. Cone Inferno on-snow base:
(Replaces Inferno kit's 2-piece metal base)
1. round heavy duty aluminum cookie pan slightly larger than the C. Cone's base
2. round piece of 1/8" plywood double coated W/ hi temp engine enamel screwed to bottom of aluminum cookie pan
the aluminum and paint won't protect that plywood enough.. it'll burn and scorch.
What I'd take if I was determined to do a CCone on snow? the cookie pan like you suggest, but sat on top of a couple layers of fibreglass welder's blanket with maybe an aluminim tray underneath. (or just set the cookie pan on top of some green logs set on the snow)