I think I have some tubs of salt too - pretty much a Pringle's tube with salt in it, got them from a pound shop!
I have some rave sticks in the bag too (glow in the dark ones after you snap them).
Oh yeh, a good thick set of jumpleads are handy.
I have a metal shovel with metal shaft from a hardware store, I dripped candle wax on it as it helps repel snow from sticking.
Not sure where to get a metal/foil blanket - maybe an athletics shop?
If you have an Aldi nearby they should have some 60 LED worklights in at the minute, charges up via plug and last for ages. Even have a hook to hang it somewhere.
Thinking about it you could go crazy with stuff to carry