I think the biggest thing to look into would be an engine block heater. On short city commutes the cold numbers kill you. Aerodynamics probably will not come into play much just do to the stop and go traffic that you mentioned. I would concentrate on getting the engine hot as quickly as possible.
Engine Block Heater
Grill Block
Front belly pan.
Tire pressures.
With an automatic it's critical to know your shift points and drive the speed that gives you the lowest rpm. That might not be the posted speed limit it might be a little ffaster or a little slower use the SG to see where it needs to be. Driving techniques are key for this environment. Both you and your wife study the 100+ driving tips to fine tune your technique.
Here's the garage listing at EM. They are respectable numbers. Just keep working on it.
Winter is a tough time for all.
