Accomodation fee of hotel during Bon festival period is very expensive

I am searching for a hotel for summer vacation in August. It’s at least one month later. However, the rooms in almost any hotels are booked, while they are expensive due to peak season. I have to book four rooms for my family, sister’s family, my parents, and parents-in-law. The Japanese government gave us about 1,000 dollars per one person for benefit money against coronavirus. I might blow the money this summer.