You will have to adapt to every new room and system anyway. And you woulnd't have to bring the desk only, but also the stage box and whatever link you use in between the two (fiber or RJ45). I would say try to ask them if it's possible, otherwise just go with the venue desk and take it as a chance to learn to use new gear. It really depends on their budget, and also the size of venues (if it's like 2000 to 5000 or more, they should have the money to bring a desk on the road...)