Special recommendations for a picnic outside during winter ? ?

ooh, that sounds so nice!! if i were in that situation, something cozy and hearty, i reckon! maybe like a flask of hot vegetable soup, some roast chicken/turkey prepared earlier that morning and kept warm in foil, and some hot cocoa! 

.................................Wear warm clothing!

Do you live in a warm climate or could you further elaborate what you mean?

Use a fire pit.  

You didn't even bother to tell us what kind of climate you live in.

Are you in Minnesota or Texas?

We are not clairvoyant.

The number of people who cannot give the most very basic of information necessary is astonishing.

Heavy coats and an open fire. At least the beer will stay cold, 

Something hot (in a flask) - eg savoury like soup, or sweet like hot chocolate

Bring one giant blanket for an excuse to snuggle close. Hot chocolate for a warm drink. Do it in a park with plenty of trees if possible to help with wind and snow.