I do keep a backup generator to the backup generator, and that one is gas. I can tell you trying to get that thing started at 20 below is a major pain, especially when it has been left outside. -Bidah
When I lived in Illinois I found a 1,500 watt blow dryer to be a very useful tool in getting engines started in very cold weather. I used it to start my Volkswagen Rabbit Diesel in -15 degree weather. I would use a piece of duct tape to attach it to the air intake portion of the air cleaner, then turn it on for about 3 to 5 minutes. It would warm all of the air in the intake and all I had to do was energize the glow plugs, hit the starter, (with the hair dryer still attached and running), and it would fire right up. It rattled like hell and belched white smoke until she warmed up, but it started.
I also had 2, Honda 250 SX 3 - Wheelers that were a bear to start when it got below 20 degrees. I built a little platform out of 2 X 4's just high enough to level the exhaust of the hair dryer at the cylinder head. I attached it with Zip Ties, plugged it in, let it run for about 3 to 5 minutes, blowing hot air right on the cylinder head at the spark plug, and they would fire right up with full choke and no throttle. My snow blower had a primer along with electric start, so it would fire no matter what. A hair dryer can put heat right where you need it on an engine to help get it started. Now, if you need a generator to run the hair dryer you could resort to a few of those chemical hand warmers they sell to put some heat into that. Bill T.