An interesting and common question with answers to match the desired outcome. Are these giant pumpkins where you grow one fruit for the biggest and only the biggest is accepted?...then pull and start over if you have a long season. Field pumpkins for numerous jackolanterns and kid-fun?--go with it, but take some time to burry the vines with soil at the place where leafstems come from the vine. Do this for the first 10 foot in all directions from the stump. This will allow and promote rerooting at the leaf stem areas to make up for the break. You should get oodles of pkns on an otherwise big healthy plant by October if you make up for the break with additional roots.