All the numbers say that due to current mortgage rates, you are best off to mortgage as much of the home as you can, for as long as you can, and invest the difference. Math says if you take out a loan at 4.5% and invest it for 30 years at the market average of 7%-10% (based on what numbers you want to use), you would be best off, based on AVERAGE returns. Of course, will the next 30 years be above or below? Your guess is as good as mine.
That said, we hated the idea of the mortgage hanging over our head. We paid ours off in 3 1/2 years and never looked back. To be fair, our 15 year mortgage was just shy of 7%, so we were only talking about a 1% advantage. Math says we did the wrong thing, and in fact we would probably be better off starting a mortgage today, but the relieve of that nugget never being a burden again is just too great for us.
The higher standard deduction only strengthens my opinion to pay it off now.
My vote is to pay in full and save like hell so you can FIRE ASAP.