5 gallon batches just don't last long enough
You have a drinking problem.
Agreed on the 20 gallon kettle for 10 gallon batches.
Best of both worlds is having both a 10 and a 20, and use the correct size kettle depending on batch size.
One of these days I'm going to get a 20 gallon kettle with the appropriate stainless basket for it so I can do BIAB to gallon batches. My current 15 gallon is just a bit too small.