Can you re-freeze milk?
I wouldn't. Milk that has been thawed and then re-frozen is at greater risk of bacterial contamination, so unless you plan to use the milk in a cooked dish (strata, cake, mac and cheese or something), I think I'd throw it out.
Can you quickly bake something with it and freeze that? Otherwise, if you only froze a quart and are taking 8 ounces with you, you're only wasting 24 ounces. Life is too short to eat risky or bad food.