Provide you have no plans to keep your insulin in direct sunlight, it survives fine out of the fridge for 24 hours.
I would recommend "insulating" it amongst your clothes where it should be fine.
Dedicated medicine cool bags will be unnecessarily expensive. I would avoid them.
You definitely want to avoid anything with icepacks as keeping your insulin too cold can damage it as much as keeping it too hot - you do not want to risk freezing it. I understand this is one reason why it has been recommended never to put insulin in an airline hold.
Regardless, in your position, I would familiarise myself with the mechanism to get replacement insulin whilst away for that long. Given the recommendations vary between 2 and 3 times as much insulin as you think you will need, that would be at least 6 months worth of insulin and I am not sure you would be able to get a prescription for so much.
I confess I am exceedingly jealous of your upcoming trip. I hope you have a magnificent time.