A few things to keep in mind....
If you are traveling to or through Canada, prescriptions cannot be refilled on US written scripts, they must be written by Canadian docs/vets.
In Alaska or Hawaii, don't assume that you will be able to find the meds/food that your pet is accustomed to will be available. Our girl has been on a diet of Royal Canon Urinary SO and doing very well. We last filled our pantries with wet and dry food at a vet in Fairbanks, but now in Anchorage and needing more wet food for the trip back towards the lower 48, we spent the better part of the morning calling and driving around looking for this brand. Some luck, but not enough to get through the next two months. Our only solution is to substitute another urinary brand, but our doc in lower 48 is not on board with this so this would require another vet visit to accomplish. Just be prepared for these challenges for any extended visit.
Another challenge. Don't expect to order and receive in a similar timeframe to the lower 48. We tried to get a refill of one of Della's scripts through Sam's in Fairbanks and a week later we still didn't have it, so we went to a local vet and were able to get it.
In general, I would suggest that all of these are true of either human or pet issues.