SSD1306 OLED module with different I2C address

So I can use the require() mechanism for modularisation of my project into several files, too?

Yes, absolutely!

You can also require("http://foo.com/bar.js") to get a module you yourself have hosted somewhere (even github).

But as @DrAzzy says, if the I2c address can be changed, it'd be great if you could submit an updated module so others don't hit the same problem