I don't run on a treadmill, but I use cycling rollers in the winter. Long runs on treadmill should be no problem. You can watch tv, listen to music, drink & eat whenever and whatever you want. Sounds like it might be kind of neat.
If you're worried about being bored, anything you do only increases your tolerances for it.
Then again, given proper clothing training outside is totally doable. It can be much nicer in many ways, including fewer ppl, better and different scenery, etc.
I haven't read the other posts and need to head out for appt, but a quickie:
foot of snow - running snowshoes
less snow - traction devices
cold - just add layers. Freezing's not hat big a deal. Below about +10F is where I start getting more cautious with facemask, etc. Freeze / thaw where you've got wet snow is, well, yucky. Layer socks or use neoprene socks or sealskinz, depending on what works for you.
I think last winter I did up to about 12-16 mi runs on packed snow (ss not needed), but hope to get farther this year. I think I did one 3-hr run on ss. "Run" may be loose use of term, but packed snow is almost like trail. Forget about paces, just run by feel and enjoy.
Up here we tend to like temperatures near 10-20F - cold enough to keep the snow dry and be able to cover skin without overheating.
I've also split runs in the winter....that is, start outside and if it gets worse, finish on the treadmill.
I've also done reverse, start on treadmill, get nice and warmed up and then head out into the weather.
The cold is the least of your worries when running in the winter. The tough part is finding places to run that aren't buried in snow. I do most of my winter running in the local subdivisions. They aren't always plowed but the traffic volume is low so there is plenty of room. Another alternative are local colleges. They are normally plowed out before the surface streets. If you have one nearby, that might be a good venue for your long runs.
Dress in layers of wicking type clothing like Cool Max or Nike Dri Fit. Any cotton next to your skin will conduct heat away from your body and make you cold. I've run at temps down to -10F here in Michigan and been perfectly comfortable in two or three layers of tights and long sleeve running shirts with a long sleeve cotton jersey on the outside to break the wind. Dress as though it's 20 degrees warmer than it really is, you should be cold for the first mile. It's better to under dress than over dress when running in the cold. Moisture in the form of sweat is your enemy.
Stay close to home if it's really cold. A fall under those conditions can be a major problem if you are rendered immobile.
You've gotten great advice. Just one other word of encouragement: outdoor winter running can be really fun! I did Boston last year, and dreaded the dark winter long runs. But there is something beautiful and exhilarating about running in the cold, and it's great not to overheat, and you don't need as much water as in the summer, and you get TONS of bragging rights with your friends. So...follow everyone's advice, and don't forget to enjoy yourself!!
The only thing I can add is to consider joining a local running club or marathon training group. I'm a lot more motivated to get out of bed on cold winter mornings if people are waiting for me to show up. Also better to have companions in case of hypothermia or a nasty slip/fall.
(who is SO ready for cold-weather running!)
Running outdoors definitely more interesting than inside. Also, from an Orthopaedic perspective (I am an Orthopaedic Surgeon / Sports medicine specialist), the stresses are somewhat different. You should try to keep at least part of your winter training outside so that the stress of pavement is not a shock to the system in the spring. Otherwise, you will need to very slowly wean from treadmill to pavement in thhe spring in order to prevent overuse type injuries from the transition. If you are planning a spring marathon (Boston, etc.), not something that you want to deal with when your training is supposed to be cresting before the event. Long runs are much easier to do outside in the winter than your speedwork.
* Visibility -- cars always win against runners...
* Layers -- especially important for 2-3 hour runs when adjustability is critical (temperature changes).
* Traction -- must be light weight for long runs -- check out Icespike (http://icespike.net ), easily the best system out there (also the least expensive of any major brand).