I'd do it a couple to a few months in advance. That's what I did and it still ended up expiring before they got my renewal finished. I had to go down to the CHL issue building to get a temporary until mine came in.My Oregon CHL expires in January. I'm thinking that if I wait until it expires then there will be a gap when I can't carry, so I should renew in advance...but I can't find on the MCSO web site how early you can renew it.
Anyone know?