I suffer from this quite a bit. I find this helps - it doesn't wholly solve it but as I said it helps.
Basically, over the knee joints, wear a couple of those off the shelf elasticated knee bandages. Failing that, try flight compression socks. Cheap enough to try anyway.
I find that calmagzinc tablets help. You get them at healthfood stores. The dose is three a day and they are like housebricks to swallow but they help me.
I saw this answered some time ago on here and it was suggested try sleeping
with your legs elevated [on a pillow]. Don't know if it works, but there is no harm in trying.
I keep my legs and feet as cool as possible - have a dehumidifier on and have cooling leg/feet gels/sprays. When I'm washing my face before I go to bed to wipe my legs down with a face wipe too. I always have a window open and have a pillow which sits at the bottom of the bed I can raise my feet on. I also find taking my painkillers before bed helps too.
Quinine will help with cramp but not with restless legs. A warm bath and raising the legs may help.
I suffer dreadfully with restless legs and take 2 prescription drugs - Pramipexole (a drug used to help Parkinson's sufferers) and Co-Beneldopa
They work.
I have nerve damage that also gives me restless legs,mainly at the end of the day and I do find that having my feet up helps.
I know you said you didnt want a pharmaceutical remedy,but I take pregabalin which helps loads.
Good luck with the dancing feet(thats what I call it when mine are having a tantrum!)
Aya