Adam,
Check out this vise made by Xyliss. It was designed for the Swiss Army and I refer to it as a "Swiss Army Vise". It is very versatile.
It clamps to anything , like a table, door, etc.; and can morph into many different things. The removable plastic jaws are easy on the bow limbs. I have had mine for at least ten years and it is very useful. They retail for $199 so they are not cheap; I found a few for sale, used, on the web for less than $100. It is made of magnesium, I think, so it won't rust outside. Unclamp it and take it anywhere.
Kevin