iRobot actually makes a dev platform that would work great for this: https://store.irobot.com/default/create-programmable-program...
Its not much more at $200 and gets you all the sensors on a roomba (bump, cliff, etc), return to dock, charging, virtual walls, etc.
Neat project. I'm a big fan of Snap Circuits so this was a cool project to see. I'm thinking of doing something similar with Sphero RVR. My biggest worry is charging the base. The ideal solution seems like a roomba (with charging base).
IMHO I feel like adding a periscope would keep your pricey phone or tablet closer to the ground and less likely to be destroyed if the platform tips over.
Holidays in 2020 are a little different. My family is spread out around the country, and due to the pandemic we're unable to gather together. To include other family members in our holiday celebrations, I built a telepresence robot from a Raspberry Pi, a Snap Circuits rover, and an iPad.