You know, that whole thing about not dragging a mortgage into retirement is so clueless. It's not directed at people who are mustachian, it's directed at the people who can't survive an unexpected $400 expense. If you have a big, fat-ass ball of investments and another of glide cash, having a mortgage in retirement ain't no big thing.
For OP, I published this elsewhere on the forum today, but I'm too lazy to dig it up. Grab a [free, library] copy of Ric Edleman's "Ordinary People, Extraordinary Wealth". It's old, but still relevant. Read the first chapter, it's the one that will help you with this question. Better still, read it with your wife. It's amazing. Short, concise and uses layman's terms. Total game changer for me on the path to FIRE. The rest of the book is fluff, IMO, but that first chapter nails it.