The extended Warranty is a lot less $$ than a tranny rebuild.
With that being said, not all transmission 'issues' have been fixed under warranty. (Original or extended)
The guy who's website has been referenced is the same guy who fixes transmissions. (And other things)
On one hand, he's pretty well versed in the GL, but on the other, he's a bit of 'odd bird' when it comes to certain things,,,
He recently indicated Honda came out with a Service Bulletin that changes the ECU reset procedures, and reportedly , on the bikes he's done,, it's 'fixed' the 'cold stumble' issue. He won't post the bulletin, nor will he quote it word for word,,, About the only difference in the procedure is 'Battery has to be 100% per the official Honda battery tester' and to ride it 20 minutes after the 2nd fan cycle.
Apparently, he's the only person who's seen/read/heard of this bulletin, and no one else can rationalize / confirm that ECU's can ONLY be reset correctly with a full 100% battery. (Lots of interesting explanations/reasoning by others on the GL forum, but none really from the 'guy with the bulletin')
I'm sure he knows more about Wings than I'll ever begin to know, but,,,, kind of an 'odd fella' in certain ways,,,