You'll be arsed to do it, but it's certainly possible.
Suggest you choose a Bangkok Bank branch near where you'll live because in the long run, it'll be convenient as you can only do many things at the branch where you've opened your account.
Bangkok Bank at EmQuartier near Phrom Pong BTS is reportedly easier than most. Pop in with your passport to obtain their current requirements list.
Obviously tell them your purpose is to obtain a visa and straightaway you'd like to transfer in the required 800k baht. They may 'ask' you to buy an real insurance policy as the staff gets a bit of commission from that, (allegedly) 🙃 555
Siam Legal solicitors can assist you, charging around 5,000 baht; but with diligence; you'll get it done.