Can I store my mountain bike + suspension hanging from the front wheel for the winter (in an unheated garage)? Switched over to my winter bike to keep my favorite away from the salt.  

Can I hang my bike by the front wheel for the winter?  Will be in my unheated storage-room/garage/shed.  My ownly real concern is the suspension.  I have a Rockshox XC 32 shock.

Edit: The average daily low in January should be about -15 C (5 F) the record low was -40 C (-40 F).
Apart from the suspension: do you have hydraulic disc brakes?
Some of them have an open design that is prone to let air in the system if the bike isn't stored upright.