Alternate CFI renewal methods
You can renew at FSDO based on activity and not worry about attending a seminar if you've been instructing. Instructing in air transport service counts.
If you're friendly with a fed (I realize the oxymoron aspects), the fed can renew you based on acquaintance. I did that for my last renewal
By the same token, another method is to have an 8710 completed and in your flight bag. The next time your POI visits and/or you're line checked approach the fed nicely and ask if he/she might be willing to renew your certificate. Chances are, he/she will.
You can make the same request when you upgrade a seat, too.
Hope these ideas also help.