Doesn't really matter which block.  Last block is 24223.  If it takes you 8 hours to patch and release, that puts us at block 24225.  If it takes another 24 hours to get the pools and exchanges to update, that puts us at block 24231.  Maybe shoot for block 24240 to be safe.

I'd wait for input from the stakeholders though.  They may be able to act faster or might need more time.