To cold to start the bikes!

Well guys I ran into a first for me this weekend. It was 18 degrees in the morning when we would leave to go hunting. My 08 WR250 wouldn't start with the electric start and the only way I could fire it was by kick starting it. The trusty CRF230 stuggled but it did fire before the battery went dead. You guys ever do anything special when starting in these conditions?
start it the nite before and put a blanket over it, a heater on the same room with the bike, or put it on the fringe of the campfire to stay a little warmer over nite.
Kick it like a real bike. The electric starter is usually not strong enough to overcome the "choke resistance".

Thats what I had to do but she still wasn't excited about starting. I run Yamalube semi synthetic 10-50 and man it felt like I was 80 weight. Once I got it fired no problem but man I was starting to wonder. Can a guy use starting fluid?
One thing that can help is fresh gas in the tank and in the carb. If there is gas left in the carb, the light fraction tends to evaporate leaving heavier components that tend not to vaporize as easily. It helps is you end your riding day be turning off the gas and letting it idle until the fuel in the float bowl is gone. That gives you fresher gas when you try to start it for the next ride.

The same thing happens to the gas in the tank.

The put a 60 or 100 watt light bulb under the engine overnight trick will help a lot. You can get a special purpose bike block heater at

Riding at 18 does not sound like a ton of fun, but assuming it warms up during the day I could see it.

My XR refuses to start if it cold soaks below about 20.

A big part of why the starter doesn't work so well is that the cold really slows down the chemical reactions inside the battery. It just can supply the needed juice at low temps.
So I want to make sure I'm understanding this. When I'm done riding let it idle until it runs out of gas. Then in the morning let the carb fill up and it should start easier? I don't usually have power when we are out like that so the heating elements and such are a no go. I guess I could put a lantern or something under them so the heat warms them a little. Yes riding sucks at that temp. Your fingers are numb you goggles freeze. But yes it warms normally by 10am.