It wouldn’t have to be the outdoor variant. It has no display so you would need a hotspot or something to keep connectivity
If you use an indoor model with a battery pack you at least have the display to view values even if there isn’t connectivity to the online dashboard.
If you buy an Open Air Max it has internal batteries and a cellular modem but right now it only charges with a solar panel with a not very common plug so it would be bulky to travel with and do display for local viewing.
I also believe the S8 sensor for CO2 gets thrown off if the device if moved roughly so not sure how well it would work for a portable device in general.
There is a different company that makes AtmoTube that is a portable air quality monitor you can use with a mobile app,
Air Lab is another mobile product with a display but it doesn’t do PM levels
Achin from AirGradient hinted at a product coming that I interpreted as a portable monitor but no official details at this time.