Have you tried the Aspercreme Lidocaine lotion first?
It is quite inexpensive and works very well for me..sometimes better than the patches.

I used this lotion for my swollen agonizing knee attack about a month ago. And it worked like a charm, with one application over the painful part of the knee once a day.

I'd try lidocaine over your sacral area on both sides... 1/2 patch on right and left. This will numb the major nerves going down the legs. If only the lower legs and feet are bothering you, I'd do 1/2 patch behind the knee, just below the bend on each leg. This placement has worked for me quite well. I do seem to have knee pain referred down the calf into the feet.

For foot only issues, 1/2 patch put on the instep (top) of each foot.

Start slowly with specific targets to see if it works for you. I don't think you should end up with several patches all over. Rotating locations is safer. I found that the lidocaine effects lasted a day or two for me, which allowed for moving them around some.