When is it safe to harvest carnival acorn squash?

First time growing acorn squash, specifically carnival acorn squash. I’ve been fighting an early frost this season by covering my individual squash at night time – this is an eventual losing battle. My squash are at different stages of growth but I think these pictures show what I have going on. If I pick these will they all ripen indoors, including the two in the second picture(they have all been at max size for awhile now), or am I best off continuing to cover and buy them as much time as possible on the vine outside?

Thank you so much for any help.