Do not start and run your engine for a short period of time. It only adds moisture to the oil and exhaust system. If you can't ride it for 15 minutes or so, leave it alone. Disconnect the battery, put it on a tender. Menards and other box stores sell some for around $20 that seem to work fine, if you don't want to spring for the high-priced spread. Most will also sell a multimeter for $20 or less that will work well enough. Occasionally Amazon has some decent ones for around $10.00. Harbor Freight as a last resort, but they won't last.
Auto parts stores sell lock de-icer for a couple of bucks, probably worth it to do that and dry out your lock. They also sell graphited locksmith oil, a little squirt will keep it from re-freezing, most likely.
If you started the bike with a battery at 11.9 volts, it's probably toast.
Lots of posts here on how to 'mothball' your bike in the fall. And how to wake it up in the spring. Most importantly, be sure the battery has a full charge before starting it for the first time.