I would suggest holding it in Oja but if the winch area would be open then Hydlaa would be better. Maybe they would come back if they had something to work for.
Events that could held should be centered around newly implemented features to show people what they are missing.
Provided I had proper storage. I could cook up a lot of food.
People could sell some of the newer weapon types, as in maces, staves, and hammers.
Some could sell maps to the newer areas like Gugrontid, the derghir outpost, and so on.
Some guilds may open up their Guild house for recruitment events.
Book readings could be held.
Non lethal arena duels could be held
Maybe a Miss Hydlaa Contest could be held. Nothrir's might have a bit of an edge with the new model.
Story telling of the latest happenings such as the crystal eclipse, the riverlings, the Tloke, etc
The House of Games could probably host a games if you ask nicely.
Ask Serq Feht if he would plan another singles event for during that time.
If Alchemy is fully implemented by then, have people selling potions. No snake oil now.
Maybe representatives for the new religions could try and convince the returning players to convert.
Hold tours of the newer areas.
I can't think of anything else at the moment.