Having just made some DIY automated roller blinds for my place, I know that it'll both be a pain in the ass to do, but also probably won't be too hard. What makes the most sense for me is a strong stepper motor on the side with a long shafts, the shafts needs slots in it and each blind piece that needs to be rotated needs to have a small DIY solenoid to engage with the shaft. You'd only be able to go one direction at a time but it'll beat running a whole lot 9f stepper drivers and motors.