A large bottle (2litre soft drink or a large spring water bottle) with base cut off and lid removed, then pushed into the soil around the plant. This protects from slugs who can eat a whole small squash plant overnight and also protects from late frosts. Squash plants suffer when it is not even down to freezing. Less than 4C and they really don't like it, even if there is no actual frost. The bottles help a lot and if real frost is forecast, then you can drape fleece over the bottles for double protection.
Your plants are still very small. Personally I'd grow them on a bit more, but if that is not really an option, plant and protect.
I have planted a few squashes, but thought about their location - plot microclimate - some of my areas are more frost prone than others. I also place compost daleks on the actual growing area. This makes spreading compost much easier and in this case as they were recently filled and are still pretty warm, they should give the squashes next to them a bit of extra protection and warmth. You may have warm spots in the garden that are beneficial for squash.
Enjoy your time away. Should the worst happen, it is not too late to start again after you return. But I hope you return and be amazed at how well your little plants have done