If I stay with M7, how long will M7 be supported?
UPDATED 23OCT2023: SAS 9.4M7 is in Standard Support until 01SEP2025. Please see this page for more details SAS 9.4 & Earlier Releases | SAS Support.
I found this from this post: https://communities.sas.com/t5/Ask-the-Expert/Upgrading-to-the-Latest-Version-of-SAS-9-4-M8-Q-amp-A-...
Maybe just something to think about when upgrading. Another way I can think of is to perform a same server upgrade. It will require downtime on the server but it will be easier for 'migration'. If I remember correctly, you just need to republish and activate the objects. If your system doesn't allow for downtime then I would go for partial promotion to make sure that each components and RTDM flow is working as expected. It depends on the complexity of the system.
Best if you can get help from a SAS I&C consultant and a SAS PSD consultant for efforts needed for such.