1 Example for SAT Essay?

I’ve been writing a lot of practice essays and I usually use 2 examples, but it always takes a long time to think of two different examples and my analysis for them, and my body paragraphs end up choppy and mostly consisting of summary. Can I still get a good score if I use just one example? I tried this and I still filled up both pages, and I was able to analyze and develop my argument more. Also, how long do most people take to brainstorm? Do you figure out your analysis and everything beforehand?