How can I downgrade my DB cluster

Hi, I was able to upgrade my DB cluster, but there is no option to downgrade it! I don’t understand why not. I can downgrade and upgrade my droplets whenever I want, but not my DB cluster? Is there a way to do this, other than backing up, destroying and creating a smaller DB cluster.

If there isn’t another way, then please help me with my case, only 2 days in the entire month do I need the additional DB memory and CPU, and honestly I do not wish to spend the extra $60 or even $90 a month, just for those two high season days, so what can I do to avoid paying more than I should.

Do read only nodes help me with this case? Assuming I have reconfigured my software, to distribute connections between primary and read-only node, for read statements, does this help me with my case, when the high season is over, I could just destroy the read only node.

Or is there a better option, cause’ honestly this solution sounds like a lot of work.

Thanks