This has worked several times, Lying in bed with the legs jumbing about, Went to the lav, did a bowel movement, and the RLS was gone when I went back to bed.
Perhaps having a full bowel or something. usually the digestive system stops working when you are aleep, and that mechanism, stopping it, that is, is not fucntioning, and some RLS is the consequence.
Not a medical fact, just seem to work a couple of times.
(rather not add a phot about that!)