What did the engine come out of?
I've seen early 6bt's in cranes with ether injection as a cold start aid. Basically a canister of ether threaded onto a solenoid valve plumbed to the intake with a push button in the cab. The push button was momentary and injected a set amount. I never liked the concept and avoided using it unless it was absolutely necessary.
The 6b's always seemed to start pretty good in cold weather without any type of starting aid. The grid heaters came about primarily for emissions.
You'd need to buy an intake, grid heater, relays, and then put the whole rig on a momentary switch of some type.
Just personal preference ,I'd be more inclined to plug it in if it's going to be that cold and skip all that.