pingc383 when i used to go to fs clinic in australia, i always had to drive 2hrs home and they always gave me the meds in a pack both at the clinic and the chemist. They were always ok and nobody ever said you have to rush home and they said it was cool if i had lunch or went shopping before driving home, so more than 2 hours was ok too. The cooler packs they use at clinics and chemists are much better that the ones you buy for lunches at supermarket. The packs were always still completely frozen after 2-3 hours and, i reckon they would tell you if it wasnt ok. :-) If that helps?
Id ring the clinic and ask and get the packs and bag from the clinic/chemist coz then you know they're medical quality freezer packs :-)