Spinal canal narrowing no cord compression seen on MRI but could this cause my sciatica pain to go all way down to near outside ankle of right foot?

Possible. Depending on which nerves are getting compressed with the spinal canal narrowing it could cause the pain you are complaining about. See a Spine Specialist to determine what care you need.
Spinal Stenosis. Spinal stenosis is usually associated with some pressure on the spinal cord causing pain in back radiating down the spine to the lower extremity all the way down to your foot and ankle.The answer is you can get sciatica pain due to spinal stenosis even if the absence of cord compression and it depends on the degree of narrowing or spinal stenosis.