I'm 37 weeks now, and personally wouldn't have wanted to go away a couple of weeks ago - not very comfortable sitting in a car for long periods, and you'll prob be feeling pretty 'nesty' by that time - everyone's different though. At the mo, sleeping is a challenge, and even strolling is to be taken at a slow pace.
Airlines won't fly you after 35 weeks anyway, so it's good that you're not going to attempt any flights.
On the practical side of things, you'd need to be sure you're near medical care should anything happen, be able to speak / translate to the nurses / docs, check insurance will cover you, and take your midwife notes.
Hmmm... from my own experience, I would be tempted to rebook and go at about 26 weeks when you're feeling a bit less whale-like, and less close to a possible birth! I went to Cuba in my 26th week, loved it, and whilst I was starting to feel tired, wasn't nearly so knackered and huge as I am now.
Question to ask yourself (apart from the discomfort factor) is that if you were to go into labour, do you really want to be in another country, where you may not speak the language, and away from the midwives who have been monitoring you throughout your pregnancy, and friends and family?