after taking it out of the freezer, you can give the milk 12 hours to defrost in the fridge and then it must be used within 24 hours. so you have 36 hours from taking it out of the freezer to use it up.
so... think that might be too late. why not use it today, and express your milk today for tomorrow?
That's what I did but i didn't manage to express more than 40mls. I really struggle to get decent volumes despite following all tips. in fact the best I do is 100mls if I express first thing in the morning, which i can only do if he misses a night feed for any reason.