The only reason I'm asking this is because recently my daughter has been taking Enfamil Gentlease powder. Last week I bought the Enfamil Gentlease ready to feed and it seems like she's having less gas and spit ups with that. Well tomotrow is going to be a long day and we will be out the house for awhile. I just read they the ready to feed has to be discarded after being opened for more than 1-2 hours and I don't have ice packs for my diaper bags. Would it be okay to switch to powder when going out (it would be easier to prepare) and then ready to feed when at home?