Getting the best Widefield results form a 350D

True, you dont want the camera to me moved.

Yeah it's for when you have no power tank and
are doing long exp.
I have a fan heater like a mini hairdrier that runs off
the Maplin Power tank I have and that would be fine.

I was also thinking about the gel heat strips you get for your
hands / socks.
Ive seen them in quite small strips.
Maybe taped onto the lens petal?
I dunno.

I'd also read a lot of the 'expert' long exp photographers
use masking tape to prevent focus slip and the like.