Of those two choices, 20' I also like the idea of having two recovery ropes. If you only need the shorter length, use one rope. But if you need more length you can use both ropes.

 

I'd take the longer one just in case you or one of your friends needs to be towed out you're not right on their tail sucking in all their exhaust fumes.

 

Not as much an issue here in New England. The areas that are treeless aren't usually areas you get stuck. The areas you get stuck in snow or mud usually have trees within 10-20 ft. or less. I have a winch with 50' of cable and carry a couple 20' straps along with a tree saver and ****** block pulley. It's done the trick for us dozens of times. Usually we just hook up a winch cable to whoever is stuck and drag them out.

 

I've had my winch out to the end. I am in a heavily wooded area, but there are times scrubby trees or nothing good. Bug is eating our spruce. Same when winching sleds. Usually a tree nearby. But I do carry some extra straps and ropes. Should get more. Need splice ends on the winch rope that knotted and broke.

 

So, I have a 30ft nylon tow strap, a 4ft braided (4 - 750lbs cords) paracord tree wrap with loops on either end, 50ft of 3000lbs braided winch line (in my winch) and a spare 50ft 3000lbs braided winch line with 2 loops (like Specta has).