My worry would the vacuum run out of charge between floors….I think I would rather have two - one for each floor than carrying It back and forth

I have an irobot braava jet m6 and love it. i use it only in the kitchen and foyer which is vinyl, but it works for any hard surface. i run the roomba first then the braava and it takes about 30 mins and uses 25% of the charge. my guess is the kitchen and foyer are about 20x20 sq ft and does good enough for me (i hate cleaning). it maps the floor and you can set it to do any room and time and day etc. i have hardwoods which requires a different solution. but you can buy another storage tank (not expensive) and have it do hardwoods on x days and all other hard floors on y days, etc.