Messmaker - - is 5000 pound enough? It depends - how "stuck" is the vehicle. Most will keep trying until they are so far in the soup that it might take a tow truck to do any good. When stuck - either have a plan( the bucket technique ) or give up immediately and get the winch.
A 5000 pound pull winch on a snatch block can develop 10,000 pounds of pull. Is the cable on the winch able to withstand this amount of "pull"??? Winch to snatch block at the anchor point - back to the stuck vehicle = 10,000 pounds. Winch to the anchor point = 5000 pounds.
Do you have an anchor point that is close enough and strong enough.
There is an old trick I learned from years of 4 wheeling in the outbacks of AK. Carry a pronged boat anchor with ten feet of cable attached. Bury the anchor at the appropriate location. Attach the winch cable to the anchor - NOT TO THE ATTACHED TEN FEET OF CABLE. As you pull against the anchor it will bury itself. Sometimes up to five to six feet deep. After you are "unstuck" - hook on to the ten feet of cable that is attached to the anchor and slowly, carefully pull it to the surface. Done properly - works every time.
Unless you go hog wild with this "getting stuck" situation - a 5000 pound pull winch should do you fine.
Now, I'm talking about a good winch here. Not some chicken s**t cheap ATV winch. Something like a Warn or Thor. Remember - you are trying to pull a heavy vehicle not some light ATV.