TheWoWDBDurotan will stay in your Garrison (after questing to a certain point) as long as you don't complete all Frostfire Ridge story quests. Ga'nar will also stay if you did it to the point where you helped kill sons of the Iron Wolf.
Edit: Just upgraded my Garrison to level 3, Durotan&Thrall&Ga'nar still there.
Elite
Durotan
Durotan is an Elite Humanoid, level 10 to 40, aligned with the Horde.
Details
Durotan at a Glance
ReactionHorde
FactionFrostwolf Orcs
Faction groupthe Horde
Level and Map Tracking
The game data tunes Durotan for levels 10 to 40, Warlords of Draenor content.
In the Client Files
Standing toward the AllianceHostile
Standing toward the HordeFriendly
Community notes from Wowhead · 1 comment
The comments below were written by Wowhead users. They are community notes, not TheWoWDB comments. See them in context on Wowhead.
Game Data
Creature ID74163
Display ID51837
Faction template2651
Content tuning64
Held item IDs94647
Related
Background
Art © Blizzard Entertainment. Fan reference, not affiliated.