The issue would be screens with a built in battery. Touch screen will also require more power. I've never heard of a monitor with these specs.
There are things like the Micosoft Wireless Display adaptor which would connect your screen to the computer, but it would also need USB power.
Could you run the USB touch-screens from a portable battery pack? Using the wirless display adaptor as well. You'd need to mock up some sort of 'case' to store it in and keep the cables tidy. Not sure how long the power would last.