The Wedding Pact (2014) on Netflix

Plot summary

Elizabeth Carter met Mitch Becker on her first day of college, and the two became closest friends; Mitch fell for her and chose not to say anything. On their final day as students, drinks in hand, Elizabeth suggested a deal: if neither of them had a partner in ten years, the pair would marry. A decade on, Mitch remains unmarried and learns that Elizabeth does too. He had believed she wed someone else years before, which is how the two drifted apart, until his friend Dave reports that the ceremony never happened. Mitch leaves his job, packs a bag and chooses the road over a plane, heading across the country in hopes of finding Elizabeth and taking her up on the arrangement.