I would suggest contacting Jackson County Sheriff Mike Winters directly.Note that Sheriff Winters is involved with some interesting business in Medford dealing with CHLs. The Medford Mail-Tribune is trying to get him to release the names of all CHL holders in the county (In relation to the lawsuit by teacher Shirley Katz against the school district to allow her to carry concealed). So he SEEMS to be willing to protect the rights of CHL holders, but it's hard to tell how that would affect his allowing out-of-state applicants with a renewal.
I'd review the information on what's going on at:
If you contact him, I'd tell him you support him in his fight against the Mail-Tribune (which I hope you do!), and explain your situation. You just want a renewal of a permit you've had for 8 years already, you travel to Oregon frequently, and it'd just be easier to do it there than at the original county of issue. I'd think you should be able to get some feel for what they'll do for you then.
Sheriff Winters direct Email address is at the bottom of the article linked above. I already Emailed him praise on his fighting for the rights of CHL holders.