Kelinmiriel wrote: »It has been available in the Crown Store since then, once. Also, there are people who own it and don't realize it.
You didn't have to be active during Summerfall to get it. You had to own Summerset, and have signed on to the game after having gotten Summerset, and before the cutoff date in October 2018, to qualify. If you did, you own it.
Go to Collectibles (U), choose the house-shaped tab on top, and see if it's listed as being owned. If so, you can travel to it from there. After you've been there once, it'll show up on the map like the rest of your homes.