Travelling home to the UK for a holiday when living abroad

Hi,

Apologies if this would be the wrong place to post this - please help me know where to redirect to if so.

I'm a British Citizen, married to a Guatemalan (Central America) and we have two dual-citizen kids.

We live in Guatemala and are looking forward to our next trip back to the UK for a couple of months with friends and family. However, last time we were back our youngest, 4 months old at the time, contracted chicken pox two days before our return flights, and we didn't have any kind of cancellation protection, etc. The cost to change the tickets was higher than the cost of buying new ones (and those weren't exactly low either...)

Hoping to avoid any sort of repeat experience, I'm trying to figure out what to do to cover us. The only airline that is really available to us, Avianca (we can't go through the US due to Central Americans needing transit visas - a different issue), doesn't offer it's own sort of protection at all. I've tried looking for travel insurance, e.g. on moneysupermarket.com, but it seems we need to be living in the UK for it.

So, what does one do when they live overseas and want travel insurance for a trip TO the UK...

Any advice (or redirection) would be greatly appreciated.

Thanks