What you could do is create a configuration entity in which you define the conditions. With these conditions, you will define/set the 'NextFireTime' (eg Next Tuesday at noon).
The scheduled event could have an interval of 1 hour. The first check would be if the NextFireTime has passed. If not, you can end the flow. If passed, you will execute the logic that you want to send your mail and reset the NextFireTime (eg one week later).
You will have to take into account that if your interval is set to 1 hour, it could be that the logic is triggered just before 1 PM, because the event could run just before noon and the NextFireTime would not be valid yet, but the next time (just before 1PM), it would be valid. So you will have to figure out what the max acceptable 'delay' of your trigger time should be.
Hope this helps
You can create one entity where you will maintain when email sent first time and who was in CC and what is SLA time , accordingly you can created scheduler which will pick all eligible row and sent a reminder.