To answer the original question Stuga will show up if you have the Orsinium unlocked. ESO+ is one way of doing that, but it is not the only way. If you bought the DLC in any way, including buying the Guilds & Glory pack or the Gold Edition of the game then you have it permanently unlocked.
If you're not sure what you've bought and what you're only renting through ESO+ you can check by opening the crown store and looking at the DLC section. Any you own will be greyed out, any you don't will be available to purchase even if you currently have access to them through ESO+.
Siohwenoeht wrote: »How do folks stand having their quest logs full?