Personally, I would go but with plans to simply have fun with no pressure. As you say, if you get swept, you get swept. Your body and long-term health should be first priority, so if you can walk and maintain a pace sufficient to finish, awesome! If not, you'll still enjoy a wonderful vacation without incurring additional costs of deferring.
One word of advice, though... I wouldn't run. Ten weeks post-op, especially after a hysterectomy, seems way too early to put that much stress on your body. Walking, with your doctor's permission, should be fine. But take it easy this go-around and save the running for the next race.