[Cob] Cob in the cold, with bears

[Iona Fairlight Hawken]

Hi all--
This has probably been covered before, but if I really want to build a cob house in a very cold area (like Maine), what are the options? Can I build a double cob wall with insulation (wool?) in between? 
Also, is cob vulnerable if a hungry bear is trying to enter? Or would it withstand a bear? 
Any advice would be greatly appreciated. 
Best, Iona