it'll work, until it doesn't work.
and the very nature of a winch is that you need it to work, when you use it, because you are stuck.
i bought a cheap harbor freight winch and a separate battery, stuck it in a boating battery box, i charge it the night before i go off road and it has enough juice for a lot of pulls. the battery fits fine behind the driver seat, one day i will make a bracket to hold the battery in place so it doesn't kill me if i wreck.
also don't be tempted to run it off one of the 12v batteries, this is called a center tap, it will drain one battery and the alternator will overcharge the other while trying to bring the lower one up.