We are nearing our FI date but all of our money is currently tied up in 401Ks.
Is this 100% true? No traditional IRAs or SEP or SIMPLE IRAs out there? You and husband did not roll-out your money to IRAs in the past?
Then fund an IRA. There is no reason not to.
If you wind up over on income - recharacterize to traditional (don't take a deduction, since if you're asking this you probably can't), then convert to Roth. This is called a backdoor Roth IRA.
If you wind up under on income, then you're good.
You don't have to guess right on these things - the IRS lets you recharacterize (switch from Roth to Traditional or vice-versa) or withdraw excess contributions up to your tax-filing deadline without penalty.
A couple of other points -
These are Individual accounts. If your husband continues to not have access to an employer-sponsored plan for the rest of this year, you could make a deductible traditional IRA contribution for him. That may or may not be preferable to a Roth IRA. Limits in this scenario are here:
https://www.irs.gov/retirement-plans/2017-ira-deduction-limits-effect-of-modified-agi-on-deduction-if-you-are-not-covered-by-a-retirement-plan-at-workRoth IRA contributions (not conversions) can be withdrawn at any time. Getting going with regular contributions could give you some wiggle-room on the ladder.
If you retire at 55, and your 401K allows it, you can make penalty-free withdrawals from the 401K.
If I'm reading correctly, you'll be about 50 years old when you pull the plug? SEPP also could be a viable option there - only about 10 years to cover, so having to take the same withdrawal every year isn't as big of a deal for you as someone retiring at 40 or 30.
Basically, there are a ton of ways to fund your retirement with what you have. So don't worry!