Choose the sunniest spot you can, and move the squash inside as soon as an air frost (temperatures below 1degC) is forecast. You can also ripen squash up in a greenhouse.
Edwin Tucker has a particularly good range of squash, both summer and winter types. Find them at www.tuckers-seeds.com (click the link below) or phone 01364 652233 for a proper old-fashioned paper and ink catalogue.