Tranny fluid level check

[Mountain Man]

Dumb Question. I am getting ready to hit the road this summer (snow almost off the streets), and thought now that I have tuned every thing, I would go thru all hoses, connections , fluids, ect. to make sure everything is ready.

Got to the tranny fluid, and had a brain fart. I know that I have to check the tranny fluid level with the engine running and warm, and at idle, but will this make the tranny hot enough to check, or do I actually have to drive the truck a few miles to get the tranny hot enough? It looks down a quart, but I have only been idling in garage, is this hot enough for checking level?

Don't want to over fill tranny.