If your presentation venue is amenable to you using an HTML/Javascript presentation framework (e.g., ioslides or remark.js / xaringan, as @jdlong and @Anantadinath recommended), I would definitely go that route. If the venue is going to insist on PowerPoint (this happens in my field), my next fallback would be to fake interactivity with successive screenshots.
However, for the sake of completeness... it is possible to embed a web browser in a PowerPoint slide via ActiveX controls (
). There is a freely available pre-built Add-In out there that will render local HTML files. Major caveat: it's not clear what web rendering engine you wind up with (it may even depend on the version of Windows on the computer where the slide deck is playing), and whether that rendering engine would support all the stuff plotly does. There's also a plotly-specific add-in, but it seems limited to embedding plots that are hosted with plot.ly.