Welcome to the Q&A Forum

My sample size is small (I am currently maintaining just four sites) but all of them include a large banner on top, which leaves 95% of text content below the fold. None of them have been penalized for this so far, and all of them rank well. As for the original question, such ratio does not seem to affect standings of the sites I've worked on. However, keep in mind that such heavily skewed page interface tends to look bad, affecting your customers' UX. I would try to keep your footer at most as large as the body of your smallest page.