Any way to see gym defenders

I live in rural area and 8 miles away from here there is 3x level 10 instinct gyms that are hold 24/7, because no other team members visit the location.

Then there is 1 gym right outside of this building and then there is 1 gym on other side of this city.

I wanna time my travel to other side of city, so i could visit it when instinct have build up their defenses, but before anyone else has taken gym down yet.