wei: 5 hrly is 2 big a gap, should pump 3 hrly if you are not latching on at all, or else your supply may drop.
Yes, you can shift the milk to the freezer if not consumed after 48 hrs. Yes, frozen milk is recommended to store for 2 months, though some said can be up to 3 months.
Once you remove the forzen milk from the freezer to the lower fridge or room temp, it will start to thaw, and you must use the thawed milk within 24 hrs. If you are going out with your dd, you should thaw the milk first, then bring the thawed milk out in a cooler bag. If the milk is frozen, you wont be able to thaw it in time for your bb to drink.