Best thing to invest in is a cooler bag that plugs into your lighter. I have one and it stores plenty of insulin, juice boxes and snacks. Test frequently and you may consider asking your Doc to prescribe a Glucagon Emergency Kit and teach your wife how to administer it. I always travel with one and have never had to use it but it's one of those things that could be a life saver when you least expect it. Finally, keep in mind the time difference and try to stay as close to your current schedule as possible.
Nancy, I had been considering one of those as an alternative to a cooler with an ice pack. do you have any recommendations? I'm leaving on Monday, so online shopping isn't viable unless I pay for overnight shipping, but there's a Walmart and a Target near my house.