Frustration with travel insurance policies, is it chemo brain or just confusing legalese?

Book the trip, Nadi.

I have absolutely no legal advice regarding how you will go if you have to cancel because of reoccurrence but if you are well now, do you really want to be held to ransom by something that may not happen? That's the sort of soul destroying stuff we can avoid doing to ourselves. If it comes back in such a way that a couple of weeks is make or break regarding more treatment, deal with it then.

Yep, that's a really cavallier attitude to your finances, and a very irresponsible attitude in general, but you did ask for an opinion.

Have a GREAT holiday