Hey Ellane,
Yes, we seem to have the same workflow. The M1 is plenty powerful, you can even do FULL HD video editing with it, some even do 4K. If you get the 16 GB Version with 8 graphics cores you will be hard pressed to overwhelm the Macbook Air. There are plenty of (long term) reviews on Youtube about the MacBook Air and ALL of them come away impressed.
If you compare Geekbench scores you can somewhat compare machines that might be familiar to you with the M1 MacBook Air. It doesn’t even have a fan built in, but even under sustained load it hardly ever throttles and if it does, it’s no more than 10–15%.
Remember the high end Intel i9 16" MacBook Pro from 2019/2020?
The MacBook Air is faster in almost every task.
Just for your information. Geekbench is an app that tests the performance of a computer with artificial workloads, these test results are pretty comparable. Higher is better.
Here's the score for 2019's high end 16 inch MacBook Pro:
https://browser.geekbench.com/v5/cpu/10527620
Here's the geekbench score for the MacBook Air M1:
https://browser.geekbench.com/macs/macbook-air-late-2020
About portable screens, there are plenty, even some by ASUS and other respectable brands and even more form chinese suppliers that seem to work fine. But you could, of course, always use (if you have one) an iPad with the sidecar feature.
May I ask what kind of hardware you’re currently working on?