I am not having chemo - thank God - but I do have infusions at the Oncologist's office. Everyone chats while there. Most say that they really appreciate having a blanket of their own. The practice has blankets but they are just the loose-weave cotton blankets that the hospital has.
The one point that every one seems to make is that their feet are cold. The office asks that you take off your shoes while having a treatment. They say that that is because shoes can be constricting on blood flow. So my suggestions would be to add a foot pocket to what ever kind of quilt/cover you make. HTH