Oil filter change vs oil change

We all know that oil will not last forever, or that an engine will not last forever without clean oil. What I cannot find is information about oil changes and oil filter changes. Yes, I have separated the 2 options.

What does the science say, not just someone's opinion? We have all been told to change the filter every time you change the oil. OK. But would the oil last longer with a filter change at say 2000 miles, ( if the recommended "oil change is 3000 miles")? Could you go 6000 miles before oil change when you change the filter every 2000 miles and still have good oil properties??

I guess you could also ask the opposite question. Can you change the oil and leave the filter?

Again, has there been any studies?

I could see using a non-bypass filter and watching the normal oil pressures. Whenever, the normal, say 75 psi, at 2500 rpms begins to drop, change the filter. Whether it is at 2000 or 4000 miles. and then change the filter at whatever interval you think is appropriate.

Finally, with many of our cars, the oil degrades by condensation and simply sitting more than use. How does that affect the oil filter and oil properties?

I guess I have too much time on my hands and I am probably thinking too hard about this. But, maybe someone has pertinent info on this.