Honestly VT doesn't not look like a tough matchup to me.
VT numbers look somewhat scary but most of it was built through their atrocious Non-Conference schedule. Kenpom ranks their NCSOS as the 341th out of 351 DI schools.
Their overal 39.7% from 3 is from 43.7% they shot in thir non-ACC schedule, against ACC opponents they shot a mediocre 35.9%. Their 3PT% allowed is 34.4% but that's also because they allowed only 29.4% from their NC schdule, against ACC opponents they allowed 39.2%.
Their strength is actually their ability to score 2s, they shoot 57% from 2 which is best in the ACC. But Duke is actually really good at defending the 2 and VT does not offensive rebound much at all (19% ORB in ACC play) to be able to negate Duke's first shot defense. Their other offensive strength is they don't turn it over much but Duke hasn't relied on TOs at all.
VT is also bad at defending 2s and particularly bad at blocking shots. Wendel Carter has double the amount of shots blocked in ACC play as the entire VT team.
Not saying they can't win, just that I don't think on paper they look that strong a threat matchup wise, especially in Cameron.