If you have more time, you can visit other famous temples in the region like the Airavateswara Temple and Chandra Bagawan Temple. For a fun-filled evening, you can also visit Punnainallur Mariamman Koil, a popular shrine for locals.
If you have less time, consider skipping Thanjavur Palace and Art Gallery. It is not wheelchair-friendly and requires a lot of walking. Also, make sure to carry sunscreen and drinking water as the days can get pretty hot and humid.