I guess if you don't mind reducing the resolution, you can e.g. average 4 pixels to reduce the noise (but I don't know if that gives you a lower noise floor than just a 16MP sensor in the first place...)
https://www.sciencedirect.com/science/article/pii/S026322411...
"...show that an array of small independent sensors is always less noisy than a large sensor of the same size."