I just had my husband measure me while sitting in a recliner with legs extended.
I am currently about 5 feet 1.5 inches tall ( I think the 1.5 inches from my height went
to my hips) and he measured from my heel, over my foot, over my lap - 60 inches barely came to my collar bone. Did not even come close to covering my shoulders.
Maybe check with the infusion center to see what is their preferred size? Or if they even want donations.
I have seen people bring in their own coverings. Some places also have heated bath blankets.
if I get too warm at night, I stick my feet out from the covers, but almost always keep my back and shoulders covered.