For mobile trading, I bring a laptop, 2 portable monitors, and an HDMI cable. By having these accessories, I can use 3 screens and if I am lucky a 4th screen connected to a TV.
As I was staying in AirBNBs for a several months, it allowed for a minimal trading setup. I could view charts on one screen, cTrader on another and more charts, news or browsing on the other screen. And if I had a TV, I could use that for additional charts. Obviously, its not optimal but it was enough to get by.
In terms of hardware, I use my trusted gaming laptop (Lenovo Legion 5 with Ryzen 7 4800H and GTX 1660ti), Asus portable monitor (AUS1641) and a G-Story portable monitor (Full HD, touchscreen). The screens are connected via USB C & USB A (My laptop is limited to a single Type-C port on my laptop). And just a note about that G-Story, it has many features such as touchscreen, multiple connection options at a very reasonable price, but I wish I would have paid a little more and got a 2nd Asus instead. The Asus looks clearer, brighter and can use displaylink which is a software based display driver that allows seamless connectivity by USB A.
My entire mobile setup is packed into my backpack with room to spare for weekend trips or even trips lasting for extended periods.