Fact check: If the vice president becomes president, House speaker doesn't become new VP - USA TODAY
USA Today
If Joe Biden is elected but unable to serve a full term, Kamala Harris would become president. Nancy Pelosi, as speaker, wouldn't automatically be VP.
https://www.usatoday.com/story/news/factcheck/2020/08/20/fact-check-if-vp-becomes-president-house-speaker-doesnt-move-vp/3399838001/