I recently had to give a workshop. To be able to do that I brought a box of stuff with me, which fitted perfectly under the seat of my wheelchair. Ideal, because that way I had my hands free to wheel.
The night before I had everything ready, so in the morning I lash that box under my seat. No problem at all, because it is not difficult and moreover I had done that before.
The day is going fine. My workshop is going well and it leads to a number of interesting conversations afterwards. In short, I am satisfied.