cold weather...run it or leave it

It is better to just leave it. Starting it and then turning it off in cold weather will build condensation in the motor. You would have to run the motor for a long period of time to rid that condensation in the oil.
As far as the battery is concerned you mentioned a trickle charger. I hope you meant a Battery Tender.
Letting the bike sit will not hurt it at all. Best to change the oil before storage.

I agree winterized the bike fuel stabilizer, battery tender, clean it, cover it and leave it alone until you can ride it not just start it

What MidIA900LT says.^

If you can't ride it for 20-30 minutes, don't bother starting it. You will do more harm than good.

Yup, battery tender and fuel stabilizer such as Stabile, Seafood, etc., and let it be. Not starting it up will avoid moisture build-up and associated problems. Make sure you DO NOT put a trickle charger on the battery. It will burn up your battery. Buying a smart-charger or Battery Tender is money very well-spent, as it senses when your battery is charged and shuts off, but monitors the battery's charge level. When it senses that it is below a predetermined level, it comes on again just enough to bring it back up to spec. A trickle charger will just stay on until the battery is overcharged/overheats, and then dies.

Noted thank you fellas

Leave it...............................

If you do use a charger/maintainer verify the charging/maintain current with a mutimeter. I have had some charge to 16.21 volts then maintain at 12.45 volts (not good).
I have started the bike many times in the winter with no bad effects. Start it up let the idle come down, turn the idle adjustment screw in 1/2 to 3/4 turn, let run until the fan cycles a couple of times. Back of the idle screw Done.
I live in a very high moisture enviroment.

I do a lot of oil changes....

What I see (in the spring) is some amount of water that comes out of the oil drain hole during the first oil change of the year. An informal survey with the owners indicate that they periodically start and run their bikes during "winter storage".

Personally - I would recommend NOT doing this.

First hand experience right there ^ ...thx kballowe!

1. You will never be able to bring oil temp up high enough to purge crankcase of water at idle in your garage. Then you get sludge.
2. Exhaust system will not get hot enough to do same, so water collects and rusts system from the inside.

Do not start over the winter.

Start it and take it for a 10 min ride. it should be fine. I usually leave the bike alone in the winter months if im not riding it. a good battery will stay charged for at least a month without a tender/trickle.