Do you know if this is only specific to 2007-2009? This sounds exactly like what my 05 LGT has been doing for years. Never stalls or throws a code, but almost stalls out when it is cold outside and the engine has not fully warmed up yet and I am in stop-and-go traffic. Idles fine though.
Are the gaskets the same for the 05 to the 07? Or did they change some small thing that makes them different? I have actually had the code for the TGV's twice since I got the car (both 50k miles or more ago) and fixed under warranty. Wonder if they screwed up the gaskets, didn't put new ones in, or what. They just said they "cleaned the intake manifold and TGV valves". Might look into this as the problem seems to be getting worse as the years go by (feels more and more like it really will stall), and it does it with warmer outside temps now (used to be if it was freezing or below, no it will do it if it in the 40's).
Thanks,
Neil