where's the pain?
entire S1 distribution I'd offer SCS
mainly foot I'd try L5 and S2 DRG
Need more information what interventions have been tried already and how long has the patient had the problem?
MRI L/S spine?
It is hard to reliably capture S1 alone due to conus movement with SCS, but it can work. I would consider a trial if insurance denies DRG, but DRG makes more sense.
Deploying DRG at the adjacent levels is the teaching point for these cases as that DRG is far too sensitive. DRG hasn't really taken off though in my area as most people are just using some paresthesia free modality in the dorsal columns. The difficulty in placing it and risk profile I think are a turn off.
A lot of post lami people have S1 radic pain and SCS seems to cover the dermatome pretty well.
But maybe your right DRG would be better.
Its a tough call