OK - I think I've fixed this. Here is what I did and it seems to work - when I upload the next release I'll know for sure.
- In X-Code, I deleted all of my provisioning profiles
- I then quit out of X-Code
- From the Development Portal, I revoked my developer and distribution certificates
- I created new keys using the Key Chain application
- Still in Key-Chain, I removed my old, soon to be expiring key/certificate
- Back on the Development Portal, I created new certificates
- Still on the Development Portal, I was able to edit all of my provisioning profiles and associate the correct new certificate to it
- I downloaded the new profiles
- I then followed this link's advice and worked around the apparent bug in X-Code to remove the old provisioning profiles from my project: Codesign error: Provisioning profile cannot be found after deleting expired profile
- Started X-Code back up and copied the provisioning profiles into Organizer
- Built for a device and tested OK.
- Built for IOS Device as though I'm preparing to upload to the AppStore and build was successful. I haven't tried uploading to the store.
I actually did the steps twice, once for the development profiles and then once that worked/tested on my test devices, I modified the distribution profiles.
These set X-Code up w/ no warning and Organizer now shows all my valid provisioning profiles that won't expire for another year. Hopefully, next year, if I don't forget these steps, I'll be able to do it a bit more quickly.