Are you only interested in momiji (Japanese maple)?

Kyoto is busy, accommodation can be hard to get, and there's no way to know whether the maple there will be turning color during your visit. Same goes for Miyajima, which is famous for momiji.

Also worth noting that ICN to KIX or another airport in Western Japan would put you closer to those spots.

Having said that, you could easily get a JR East 3 day pass and visit spots in Eastern Japan with good foliage - but not necessarily momiji. Japan's meteorological agency always publishes updates in the fall to help people find the best foliage as the season progresses.