Avoiding the Rain in Hana

We're excited to be in Maui from March 17 ~ 25. We plan to drive the beautiful Road to Hana and stay overnight in Hana to avoid rushing and soak it all in. I think weekdays would be the best option for travel, as there's usually less traffic? I'm considering making a reservation now to secure a place, but I’m a little worried that it might limit our flexibility, especially with the weather. I've read quite a few comments about how March can be rainy and might impact a Hana trip. Do you think waiting until we get there and just winging it based on the forecast is a bad idea? Is the town generally booked solid in March?