the first frost of the year was on sunday night, i checked my pumpkin patch today - tuesday - and everything seemed fine. the temperature dropped to -1*c so it wasn't a hard freeze - the weather network also posted a frost warning. the only difference i found was that top colas were 'browned' and withered a bit but the rest of the plant parts (colas underneath, leaves, stems, roots etc..) seemed intact.
here are two photos of the top cola of one of the plants. the first one is from friday (before the frost) and the next one is from tuesday (2 days after the frost).
hope it helps as i had no idea what to expect as well...