I use one of these
https://www.amazon.co.uk/dp/B07YF95RNR, some bluetooth peripherals, and a little phone tripod. I have it set so that when a monitor is plugged in, DeX starts automatically, so when I'm at my desk and plug my phone in, in 2 seconds I'm ready to roll. I also use DeX with my AR glasses (Nreal Air) when traveling, which basically behaves like a full-HD monitor on your face.
My termux session runs permanently in the background out of laziness (though this does noticeably shorten your battery life, but it's been mostly manageable) so all I need to do is start AVNC.
There are a lot of little configurations and quality of life things that I tweaked over the past year or so of doing this; happy to write all those up somewhere if you're interested.