Hi there,
Im newly diagnosed myself but had to ask about travelling as we are booked up to go abroad as well.
From what the Diabetic clinic have told me and what i've found out you will need a letter from the clinic explaining your son is diabetic and to carry this on you for the airlines etc so you will be allowed to have his insulin and needles on board. Also if your travelling to an EU country apply now for an EHIC card
http://www.nhs.uk/NHSEngland/Healthcare ... -ehic.aspx the card entitles you to the same health care as a rsident in the country you are in (Thats assuming your travelling within the EU) it can also sometimes mean you have discounted or free Health care depending again on the country. As far as health insurance goes we called the post office and they said normally because Im diabetic there would be a slight increase however if I have the EHIC card then the premium would be a standard premium no extra cost as long as were within the EU (Again different insurers may vary this)
There will be others who will know a lot more than me thats all the basic info that I've been told and found out so far.
Good luck, and have a nice holiday