So if he's emotion driven, will he just trust you on the math? If you said something like "hey husband, we've got plenty in our taxable account, and I'd like to get more in our tax advantaged accounts, but since I won't be working any more I'm not allowed to contribute to a 401(k), so can you keep filling yours and we'll live off our savings to do that?" would he go for it?
Another idea: You can also both contribute to IRAs based on his income. The limit will be $12k + $1k/person catchup if you're over 50 or box 1 of his W2, whichever is less. If him maxing out his 401(k) would drop his W2 income below $12-14k then that would be another reason to have him contribute to Roth 401(k) if available since that doesn't reduce W2 income, so you can basically double contribute. Or, "worst" case, even if he doesn't want to contribute to his 401(k) you could contribute to your IRA and maybe he would be willing to contribute to his IRA since it would be a more direct transfer from taxable to IRA without feeling like his salary was $0.
Something you might not be familiar with if your income has been high until now is the
Saver's Tax Credit. It won't work if you withdraw from your IRAs, but if you're living off of taxable and your AGI is low enough it would.