I'm having a hard time assuming 375K compounded at an unknown interest rate between now and the next 22 years is going to be enough.
If we use 3% real return after inflation, that is around 725K in 2013 dollars. 7% is 1.7M.
You asked, "Is continuing to contribute to the 401k (for the tax benefits and the match) affecting the time to FI? "
Yes.
Any money you have socked aside is going to lower your time to FI. Why not match dollar for dollar up to 4% of your husbands base pay if he contributes 5%? If your husband is paid 100K, takes 5k and puts in his 401K, and the employer gives an additional 4k that is an immediate 80% return on investment. Plus, an immediate savings of whatever your tax rate is on the 5K. If you were in the 28% tax bracket, that is $1400. I'd have a hard time turning down taking 5K of my money, and turning into $10,400.
Paying extra on your mortgage is not going to equal those returns in the paragraph above. However, paying your mortgage off early in addition to the 401K contribution is a good idea.
What I would do is contribute the min to the 401K to get a full match, fully fund a Roth IRA, then split the difference between remaining funds to pay off the mortgage early, and investing into a taxable account. As well as having more money set aside somewhere for when your house needs a new roof in 15 years, or any other unknown event that is going to require lots of money to remedy.