@danh1977 for the length of a flight, provided you keep your insulin in your hand luggage and out of direct heat, you should not need any travel kit for your insulin.
I have travelled to the US often for trips of one and two and more weeks and, unless the weather forecast at my destination is hot, I don't bother with Frio. My insulin has never suffered.
When I have needed Frio, I only have the wallet and everything has ben fine. This has been on long camping and trekking holidays in very hot countries (India, Venezuela, Ghana, Morocco,...) with no access to fridges.
More importantly
- put absolutely nothing diabetes related in the hold. Your hold luggage may get lost and then you will be without your diabetes treatment. If your carry on luggage is too small, you can ask the airline (in advance) to allow you to take a medical bag with you. I have never needed this so don't have experience.
- take at least twice as much of everything than you think you need. If your meter is powered by a battery, this includes spare batteries.
- do not put your hypo treatment in the overhead locker during the flight, especially during take-off. I have had a hypo whilst taking off and been shouted out for getting up to get my hypo treatment
- ensure your travel insurance covers diabetes.
- get a letter from your doctor to explain why you need a diabetes kit including sharp items. In 15 years, I have needed my doctor's letter once but do not fly wthout it for fear the medication and supplies which keep me alive are taken away from me.