I've had this problem with a couple of different projectors, usually with resolution of 1024x768 or less. In Chrome, select "Zoom In" to make the font size larger (and easier to read from a distance). Eventually the page will switch to mobile view (you may also need to resize the browser window). The sidebar menu items will render over each other vertically.

Unfortunately, (1) I can't replicate this using a regular second monitor and (2) I couldn't grab a screenshot since I was in the middle of a demo.