There is no good answer I know of. We had a pair of Shelties for 12 & 16-1/2 years. Took us 1-1/2 years to get over the loss and get another pair, they lasted 14 & 16 years. It was even tougher after those two, that was over 5 years ago. We miss them all terribly, they improved our lives every day, but we haven’t been able to bring ourselves to start up again as the end is so tough. We’re away from home more and we travel more, so we tell ourselves we don’t want to have dogs only to leave them in kennels more often…
One thought, my sister has fostered a series of pets, might be another way to go? She gets attached but they’ve all gone to good homes so she can live with that. You miss them, but there’s another to keep her entertained, and she doesn’t get as attached. And the commitment is much shorter so you can change course if necessary.