Can I connect three monitors and provide power to my MacBook Pro with a single cable?
Official Apple specs

Officially your MBP supports two external displays at up to a maximum resolution of 4,096 x 2,304 pixels at 60 Hz at millions of colours or a single external display at a maximum resolution of up to 5,120 x 2,880 at 60 Hz at over a billion colours.

So, running the two external displays along with your built-in display is officially supported.

Unofficial real-life scenarios

However, unofficially you can exceed this. More specifically I've seen a user connect three external displays while in clamshell mode. However, this did seem to result in the MBP's fans spinning at a higher rate when they were watching videos, playing games, etc. Not something I would really recommend.

Your setup

So, I wouldn't recommend three external displays. But, as for your setup, you say that you only have one free USB Type-C port. So for you to do what you want may require you using your ports differently so that you have at least two displays connected directly, and another different display connected via an adapter and your other devices connected via a dock or hub.