Just like practically everyone I guess I had an ad from the ‘hellosunny’ shop (see below) for Waterproof Shoe Covers. I had spent a lot of time on this idea before coming up with my own 13 gram DIY version (https://www.theultralighthiker.com/2017/04/14/19-gram-dyneema-camp-shoes/) which have proven very serviceable and durable on many trips now.
I guess that not everyone can sew (which is one reason why I am always coming up with new ‘no-sew’ ideas (watch this space eg for inflatable quilts), but a search turned up a multiplicity of such shoe covers on dhgate many of which might be very good for camp shoes when you only want to keep your socks dry when answering a ‘call of nature’ in the middle of the night.
They range form just a few cents each, so you should take a look: https://au.dhgate.com/waterproof-plastic-shoe-cover-australia.html & https://hellosunnyshop.com/products/covers?fbclid=IwAR2PbVL929OHMCsjvySi0_gkEtcdyzzTLmfFf__rgA819LOb_7b52DqbTug
I bought some from Aliexpress for US$1.50 each. The size Large weighed 29 grams each fit over my US Size 9 (Mens) shoes, so if you are just putting them over your socks you should go down a size or two.
Some borrowed pics to whet your appetite: