Any chance my pumpkins will last till Halloween?

They are already quite large (think the kind you would pay $10 for at the pumpkin farm) and almost completely orange. Tomorrow I will be putting them (carefully) on newspaper per Rhonda's suggestion, but I am wondering if they will even make it to Halloween. Obviously keeping them on the vine as long as possible would seem to be the best idea, but is there anything else I can do to keep them going? There are two vines, two pumpkins (not hand-pollinated or picked off, just chance) so this is my only shot....