Long before diagnosis, I travelled extensively in Australia, New Zealand & SE Asia. Since starting on insulin, I have continued to travel independently and as an expedition leader, although more in Europe, Scandinavia, North Africa, Middle East and Latin America - longestr trip was 4 months in Chile, Falklands & South Georgia. To keep insulin at the right temperature, I used fridges where I could find them eg hostels, barracks, cafes, restaurants, ships etc. In between fridges, I prefer to use stainless steel vacuum flasks, rather than Frio pouches, as flasks offer more physical protection against knocks & vibration. Obviously, for air travel, flasks have to be empty of water, but if insulin cartridges are cool, and you don't put flask / bag in direct sunlight, on a radiator etc, it won't get too hot.
There are rules about how much NHS supplies you can take from UK, so you'll have to bear that in mind, but most people can take enough for several months. To reduce bulk & weight, you'll probably want to consider reusing lancets and pen needles. Australia, New Zealand and some other non EEA countries have reciprocal health care arrangements for UK residents - see
http://www.nhs.uk/NHSEngland/Healthcare ... tries.aspx Basically, UK residents can get same healthcare provision as residents of the country they are visiting.