Yes, u can stay in the lobby while waiting for the timer to count to 0.
Thanks. Will try when I reach this stage. Is there sufficient time if I find an ex raid to do this? I know at times last 15 min can still have enough people to clear the raid. Maybe I'll break up this into different days to complete. Each raid pass I'll do like 3 timeout with solo private group, then leaving enough time to do the final raid in the public group. Hopefully I reach this stage before NN found this and nerf this.