I assume You meant "put it in neutral and let the engine idle", if not no way,pull the shaft.
If You did mean that, I've pondered that as a "what if", no tools/wrecker/tow strap/only
option. But this isn't an emergency,so no reason to test that method.
I dropped the shaft on my '64 GT vert to dolly it from OK to PA, and it is a 3 on the tree.
The thought of it catching a gear at 65mph and waggin' the ***-end around and ramifica-
tions to follow didn't appeal to me. A word about those dollies,as mentioned check the straps
often and back them up w/your own ratchetstraps/chains.If the roads are rough,check the
lamp housings to make sure they won't turn in the fenders. I had to pull over and repair the
wiring twice when I realized the harness wasn't just twisted as a matter of manufacture!!
The last fix involved jamming mech. wire in the led connector,wrapping the broken wire
'round that, then stealing a couple trim screws from my car to run into the fender to lock
the lamp in place. Getting pulled over doesn't appeal to me either, esp. out if state!
I'm curious what trailer You're considering that an A-body is a questionable fit??