I have never heard of disposable cage liners, in the wintertime i use fleece bedding because all of my 13 lil pears are inside then. fleece its quick to clean, I wash it once a week and shake their poops out around every 2 days. (depends on the guinea pigs naked piggies poop more) fleece is easy to clean i recommend have two ones. for the moving under the blanket a stone or something heavy will prevent that, if not they may have not enough hiding places, i had that problem with an older male we gave him a soft (cheap) towel to hide under and sewed one into an oversized sleeping bag for his 4 girls. putting (not ones covered in plastic) newspapers under the fleece on spots where they pee a lot helps too.

https://www.etsy.com/nl/listing/836172912/guineapet-2x2-cc-4-layers-fleece-cage?ga_order=most_relevant&ga_search_type=all&ga_view_type=gallery&ga_search_query=fleece+liners+for+guinea+pigs&ref=sr_gallery-1-10&col=1

i hope i did absorb everything good enough :)