Butternut Squash

My butternut squash are a pale yellow/tan colour but the skins are not very hard, I covered them with fleece before our first frost and they are still on the vine but all the leaves are dead and removed. If I harvest the squash and place them in my unheated greenhouse will the skins harden and if not will they taste the same if eat them as they are?  I know I cannot store them for long without the skins being hard, but hopefully I can cook and freeze them?

I will be grateful for any help you can give.

I did that 2 or 3 years ago, but the sun came out and the greenhouse got quite warm and they ripened. However, I live in France so my greenhouse may be warmer than yours in the sun and England has had dreadful weather this year. The skins are quite thin anyway, but they do get very hard. The flesh should be deep orange. I think it would be best to store them before eating them as normally the underripe ones sweeten with time.

Thanks for your help Busy-Lizzie.  I removed the squashes yesterday and put them in the greenhouse, it's been lovely and sunny today so a few more days like this and they should ripen. This is the first year the squashes have not ripened before the first frost and your right the weather has been pretty awful here in the uk however surprisingly we had our best sweetcorn harvest for years.

Sweetcorn likes water. The farmers here have enourmous water sprayers and they use the water from the rivers.