'cos it's bloody expensive so I'm hoping 1 x 20kg allowance will do? We travel fairly light and will be going to Spain in the Spring, so hopefully t-shirts, shorts, crocs, rather than big boots and jeans!
It's our first holiday abroad since having the children - 11 years and counting - so I have NO CLUE, but just booked for 1 suitcase to keep the costs down...