Best way to "stop" Aurora RDS PostqreSQL read instance during off-peak hours?

We have an r6g.large write instance in our cluster which is perfectly enough for us during off-peak hours which is about 16 hours a day on workdays. But during the 8 peak hours we would need a larger instance let's say an r6g.2xlarge minimum. Between the peak and off-peak hours it's not allowed to have any downtime! Our solution would be to have the r6g.large write instance and use the r6g.2xlarge reader instance during the peak time. But in the off-peak hours the reader should stop completely. But to our knowledge this on demand 6g.2xlarge reader instance can't be stopped this is a limitation of the stop function (right?). So what's the best practice to do this? Delete the reader instance every day and create a new one? Is it a good way to do it? Seems a bit odd because we lose all the metrics and reports but running it 0-24 costs a lot. (We tried serverless V2 but it's buggy and expensive, it has random spikes and doesn't scale down to 0.5-1 ACU we tried everything.) Additional info: Our database is 700gb which may take a lot to start. Does it have any associated cost with it (like data transfer usage as Aurora is multi AZ)?