I expect Miyajima would be absolutely packed on. The first but book now and you might be able to score somewhere to stay on the island. If you wanted the full New Year’s Day experience you could hike up komagabayashi for the sunrise. ( I did this once on a hot summers day and was so happy to slip inside a hotel for the onsen before heading back to Hiroshima)

One fun thing you can do heading that way is take the sunrise izumo/seto night train. The pass covers it but you have to pay extra for a cabin. It’s the last regular sleeper service in japan and no idea how much longer it will last. We rode it after visiting a sake brewery in country Okayama and it was a lovely way to get back to Tokyo, especially after a massive yakiniku dinner by the station and a really great bottle to fall asleep with.

A trip to and tour round a sake brewery is a really interesting thing to do. A tour round the production area needs arranging in advance, especially around new years, peak brewing season. But there’s a lot of breweries that are a good day out. Kumazawa Shuzo is a good one near Tokyo. Not only do they brew sake but they also brew beer, distill gin, bake bread, make sausages, run a cafe and an amazing restaurant. It’s only a short trip outside Tokyo.