As a short term solution (I don't need to take that many long rides when its cold), I crack open a few of those instant hand warmer packs. They are about 40c each from a sporting goods store. One goes in each chest vent on my riding jacket, and I tape one to each hand grip (the small ones, so that most of your grip is not affected). Then you can alternate one hand over a warmer to warm your hands up (I just reckon its safer that way).

If I had to ride more in the cold (and down here in S. Louisiana, that's not terribly likely), I'd invest in heated clothing. My normal commute is under an hour and I'm toasty in the mid-30's in thin lined leather gloves (can't stand not being able to feel my grips properly), my full face helmet, chaps and my lined textile jacket.

 

K: Don't sweat wearing the pantyhose for a minute. The Denver Broncos wear pantyhose on the really cold days they have to play at home on their outside field. ............. Most ski/snowboard gloves now have that small zipped pocket on the back of the glove for the thermal insert. Works like a charm. .... There is a product available over the internet that "wraps & seals" the bottom of your helmet. ........... I spent 4 winters in Alaska on snowmobiles up to 90 mph. Sure, you felt a little like the Michelin Man, but never felt the cold. ........ Lemon Pledge applied to both side of the helmet's face shield helps considerably when fogging is a problem............... BC

 

Bought a pair of HD heated gloves and they are GREAT!!!

 

I have a 75 mile commute to work. Lately it has been clear and mid to upper twentys. I wear an FXRG cold weather rain suit with liner, HD heated gloves, HD thinsulate Balclava, a liner out of my leather jacket and insulated boots. Works good, lasts a long time. I just bought a Fulmer "modular" full face helmet. I really like it. The whole jaw opens up making it like a 3/4 helmet to put on. Way easier than any other full face I have had. I have been in the rain in the 40's with this suit and it really keeps it off of you.[&:] Hope it helps.

 

I used to do a lot of snowmobiling. They make heated visors that absolutely REFUSE to fog up. Check out this link I used to ride in -30 weather on that sled, and never had a problem with the thing fogging up. It does not draw that much juice as snowmobiles only have magnetos and no battery. The lenses are helmet specific, but if you don't see your helmet on the list, you might be able to call the manufacturer and see if there is a lense that will fit your helmet and one of their snowmobile helmets. Just run the pigtail up to the right hand grip, then run the wire from the lense down your right sleeve and plug it in, you will not even know it is there and your lense will never fog up.