Which direction do most of your prevailing winter winds come from (in my area they come from the northwest)??? Place the ventilation on the opposite wall(s) so that icy winter winds don't blow in.
We live in the Midwest, the ventilation opening is high on the east side. There is a window on the north & south sides, walki-in door on west. During the winter we close the north window but leave the south window cracked.
I'd open up the eaves both on the low and high sides, cover with HC of course.
Then put a big vent up high on the run side as it will be protected from all weather there.