Have you ever been to The Fort before? If not, I would go because you will want to go back regardless of how impacted your trip is. Many people will be reporting about the construction between now and then and you can make a decision closer to that time. I have reservations in the fall and will certainly report back what I am seeing. I would say you can find many places to walk your dogs even if the path goes away. The dog park is just down from the 100-300 loops and should be available.