5 hour car ride with frozen milk?

Ca
Hi ladies,
I exclusively pump for my 5mo daughter who has a cleft palate. We're going to a wedding next weekend and dropping baby at grandparents on the way. (I already miss her!). I'll be bringing about 90oz from my freezer stash for her and am wondering the best way to do it. Will it stay cold enough if it's packed in ice in a cooler for 5 hours and then put right in the freezer when we arrive? Or should it get put in the fridge when we get there? 
All the milk will be used Friday-Sunday so if it thaws out a bit on the drive on Thursday night will it still be good on Sunday? I know fresh milk in the fridge would be but I'm not sure about freezer milk. At home whenever I thaw a bag it gets used in 24 hours. I don't think we can make dry ice happen to keep it cold cold so would love to hear anything that's worked for you guys!