I guess it depends upon your definition of "travel". Going to and from the office, you don't need a bag... at least not because one is taking a tablet. If travel involves flying, then there is a HUGE difference between the 9.7/10.5 and the 12.9. I've never taken a flight where my 12.9 Pro was comfortably usable on the plane. Quite the opposite with my 10.1 Lenovo Yoga Book (Android)... which is virtually the same size as the 10.5 Pro.
I had no problems flying with my 12.9 at all....But for remote work with Jump Desktop (that you also used heavily as I remember) it makes a huge difference to work with the 12.9 (that has a resolution similar to a 13"-15" notebook) compared to the 9.7 or 10.5....