I wouldn't stop the metformin because there is some evidence it helps with neuropathic pain so may be contributing to her comfort even though the  insulin is still high.

Have you looked into empagliflozin?

Are her minerals balanced?

Have you done a domperidone stimulation test for PPID or considered treating with pergolide during the seasonal rise. Winter/cold induced pain can be managed.
--
Eleanor in PA

www.drkellon.com 
EC Owner 2001