Staying past 20 years....
could make you more eligible for 1 yr remotes. Since the return date from a 1 yr tour must be prior to our 7 month DOS, an extension would make you eligible for more remotes. Subtract 19 months from our DOS and that's the latest point they could tag you. Now you are eligible all the way to 20 years. Declining the 1 year remote (3-day opt) would leave you with no retirement. I guess if you like our current location you could volunteer for a remote with a guaranteed follow-on back to your current base leaving our family settled for about 7-8 years.