Most all the major electronics manufacturers offer ice packs for ice fishing, I had a Lowrance 522c IGPS
I used for years ice fishing, now I'm useing a HDS 5 and my son uses a elite 4 we've never had any problems.
All we use is pop up or flip over shelters or just sit on the ice nicer out, they all have been exposed to well below zero degrees riding around in sleds and on snowmobiles.