Even when I used up hours he was still there, so I assume sages can now be encountered in the region at any time (by anyone?) until they travel to a different one.
Yes, he is not dependent on your hours anymore. That's one of the changes you will like.
And congratulations. You're the first posting an encounter, and there's quite a bit of info to be gained from that for the people who want to find out how the new system works.
