Where are you getting 2.375 for a 15 year mortgage?
I think you should run a couple of calculations. As a previous poster said, determine how much interest you will save over the course of the loan. Then run some numbers as to how much you would have at the end of the term if you invested that money instead, using whatever growth rate you are comfortable with. I did this with mine and decided to do the refi instead of investing, but my mortgage is much smaller, so I was only using $150 a month, not $930. I also have enough other money going into 401k, IRA, HSA and taxable accounts that I figured it was worth it to direct $150 extra to my mortgage to pay it off quicker. I wanted my mortgage payoff to coincide with my FIRE date.