[brucepick]

Right now it's 273º Kelvin here.
Just had to get my two cents in.

Anyway, yes, winter is a bear on your mpg.
All the tips given are good ones.

CAPTAIN CHAOS, consider boosting your tire pressure. I regularly run mine more than 10% over sidewall max. I'm not saying you should go there, but you might set them to sidewall max on a cold morning before driving. The engineers and lawyers know they will go up a few psi from daily temp increase, AND also from driving - so sidewall max when cold is fine, in my humble opinion.

Using lots of EOC will delay full engine warmup. However, that is more efficient than achieving a warm engine by letting it run when not needed. Sometimes, I've nearly achieved my usual average mpg after a short 5 minute drive, and the engine is still relatively cold. Due to lots of EOC. It's a GOOD thing.

Grill block, insulation if its done safely, and block heaters of various types, will all help.

Quick manually adjustable grill block - if you have an opportunity to adjust your grill block once warmed up, say after 5-10 minutes drive or so, you can do a more thorough grill block for startup and then remove some blocking later. I've done this. Good if you're doing errands, or dropping off a kid at school, or picking up a carpool partner.