I doubt it. I'm not sure whether it's possible with squash at all. But when you do this with plants like strawberrries or clematis it takes quite a while for the roots to develope, and with squash you only have one summer. Some plants will wither (read rot) if you do this.
I know that some people pierces cucumber plants right behind the fruit and put a wick into this hole letting the fruit develope without taking water and nutrients from the rest of the plant. I quess this would work for a squash as well (if it actually works, and it's not just some kind of gardener myth), however, I doubt it would work for a whole plant.
I would probably try to separate them, love them a lot, cross my fingers and hope for a late harvest, OR pick out one or two good plants (or three, as I have NO idea how big an 18 quart container is) and chop down the rest just above the soil, leaving the roots of the remaining plants intact.

18 quart would probably be almost like a 5 gallon pot or 60cm diameter if it were shaped that way.

10 plants in that size is kindof alot! LOL But I know that I have jammed alot of plants in small containers and what happens is that a few will become dominant and take over and the others will become dwarf. You could probably get away with jamming about half in there and maybe 2 or 3 will become dominant. It's just that with squash, the leaves become so huge that they really may shade out everything else in the container. You could always leave them in the pot and snip off any "weak" plants right to the soil line and keep the strongest plants. That way you won't have to transplant or disturb the roots.