So satisfying. I needed a break from early BfA war campaign grinding so I worked on my Dark Iron Shaman instead.

Got her from about L88 to 96.3ish and garrison set up before she ran out of Rest.

Let's see if I can do much the same with my Mag'har Hunter.

Very close! Followed the same pattern, as closely as I could remember - level pets Outland > Northrend > Pandaria (missed 2 due to rollover, but I'd repeated Northrend), do Pandaria starting quests to enable the portal, hit 90 and proceeded to WoD starting questline, cleared land, established garrison, collected resources, and got 1st follower.

Arataki is a few bubbles short of Dorchae's progress, but she also retained 2 bubbles of rest.

Does the Faire buff also stack?

Haven't tried yet.