Stance Men's Slipper Socks ~ rowan slipper black

I love these sock slippers and have purchased two pairs as a result. I find them unique in that I don't come across sock slippers frequently and I love that these ones have the grips on the bottom. I bought a pair for my mother, also, who is a senior and currently been admitted to the hospital for a couple months so they're good for her to keep warm and walk around. The only concern I have is I find they feel like they fit true to size, but I also find they kind of slip off my get pretty easily too. You would think because they're a fairly tall sock, they would hold well. But the top of the sock slips down easily. I expect this considering the sizes (S, M, L) each range by a several feet sizes.

Warm but material bunches up under toes so not comfortable.