I would think that all dragons would do drastically different things. Dragons come in an incredible amount of flavors and the thought processes and life systems of GDs are so vastly different that generalities most likely can't be made on that score. That said, you paint a pretty good picture for where this adult dragon you are talking about is now, so here is my take.
Firstly, he's going to need to set up shop somewhere. While his public holdings got taken from him, he was likely clever enough to keep a fair bit of cash in hidden accounts (not to mention any stash that he has left over from a previous age). Moving to Seattle is an excellent way to stay under the radar and quietly plot your revenge, so I am imagining this to be the dragon's motives.
This means he is probably moving into either the outskirts of the city, or a barren part of the city, any place where the rich and powerful aren't poking their noses very often. Depending on his financials, his new lair in the area is likely a run down building with a nice, mostly collapsed roof, or a certain section of sewer that he has spirits getting all nice and clean for him. It possible he got a special place made for him through a speaker, but dragon's living in caves? Passe, these days they most likely live in the nicest, and most private, estate they can afford. Niceness can be waived, but privacy is key.
Hunting would be a very high profile task, especially in and around Seattle. Likely he has picked up a speaker already, or has a new one he trusts from the Seattle region who would arrange for food deliveries. The quantities are suspicious, but no more so then one of the larger ghoul enclaves.
I would say luxury all the way, especially the younger dragons. Most of the dragons that I've heard about are immensely interested in the changes that occurred while they are away.
A dragon has to have its hobbies, likely your boy is looking at a long (read decades) plot of vengeance to wreak on the Azzies. This is likely amusement enough, along with building his power base in Seattle, this would eat up alot of his time. Dragon's tend to leave little to chance, so thats likely what he is doing. His magic does not amuse him anymore, he has had it for 1000s of years, I think he would be much more amused by a high budget trid-show. Perhaps he is addicted to a soap like "Passions"?

But hey, this is just my take, for any given dragon, I don't think you can put a template down for how they act...and I think that's kind of the point.