Well it felt like the moment we made the correct call, things started to go better, but perhaps that's just confirmation bias.
First of all we found a surprisingly affordable flight to London (thanks Sash), which after flirting with a cheaper flight to Istanbul followed by a road trip across Europe... was the less exciting, but more sensible option.
It wasn't all easy; F contrived to puke all over himself and KFC at the airport (BTW if you're ever stuck a KL airport with kids, KFC have a great indoor playground). But other than that our long wait for the plane went well.
On our first leg (2hrs to Bangkok) a family sitting next to ours with a 16month year old baby started emptying a typical firstborn's travel toy collection onto the floor, D made her way across the aisle and was entertained for almost an hour. D as a no.3 has had to settle for one stuffed toy, one baby book and a couple of teething items on this trip, not the entire suitcase worth of equipment her young neighbour had at his disposal.
In Bangkok, my dad then called us by accident and when I called him back, he offered to pick us up from the airport the next morning despite the ungodly hour - result!
By our second flight (12hrs direct) we were all tired; F was asleep before take off, G went through her normal hyper half hour on the way up, then fell asleep on my arm. Finally D calmed, then crashed, Ali and I quickly followed.
7-8hrs later we woke up, watched a couple of movies then before long we were at Heathrow. We collected our untampered bags - we'd taken precautions:
And we were back!
To top off our change in fortune D slept through for pretty much the first time!!