When I had my mk6 GTD, it used to idle at around 1,000 or slightly higher until the engine had warmed up, and it took longer to warm up in the colder winter months than it did in the warmer months. So I’d say that 1,000-1,100 rpm at start up and before the engine gets up to normal operating temperature - especially this time of year when the weather’s cold - is normal.
As Mkgti suggests, after a 30 min run it sounds as if it was in the process of performing a dpf regeneration; increased rpm when the engine’s warm is a tell-tale sign of a regen.
