I’m in a similar situation: I travel every couple of months and while the iPad is great for nearly everything, it’s still not able to completely replace a Mac for me: when I really need a Mac, I need a Mac.
My solution was to buy a MacBook, ‘cause portability is what they’re designed for. It’s always ready to be used no matter where I am (airport, hotel, remote site) and it always has a working keyboard and display (and power supply/battery). I’ve never been sorry about going with a notebook over a small, portable computer.