Being as it's holiday time, I thought I'd post this fyi anyone who is still in a cot after the "standard" age of about 2 years which is when most travel cots seem to expire. (You probably all know this, but I didn't so I thought I should post it....)
For anyone who has a Babydan Babyden, you will realise they can be made into different shapes other than the hexagonal configuration. If you put it together as a rectangle (1 panel x 2 panels) then the dimensions are 122cm x 60cm.
It just so happens that the standard continental cot mattress (as available from Ikea for £29) is 60 x 120 cm.... and fits like a glove. The babyden is a bit heavy to fly with, but they now make a lightweight version though I don't know how robust that one is. Or you can chuck it into the car for closer trips.