winter fuel consumption

[200q 20v]

Every winter my 200 becomes a gas guzzler. With the coldest winter on
my ownership on record (global warming?) it has been the worst. It is
approaching consumption of a 4.2 V8  in city driving. There is no loss
of power, fuel smell, unusual exhaust, etc. VAG-COM data appears to be
withing recommended limits.

The only observation is that when engine is cold simultaneous clutch
disengagement/gas release while driving with no acceleration (2nd or
3rd gear) on a horizontal road results in noticeable RPM increase for
a fraction of a second. If accelerating it is even more noticeable.

Has anyone seen/solved anything like this?