Totally understand about the accounting issues it might create.
I suppose the only thing I can think of might be if DH could apply for the Hilton Aspire today (using his Platinum referral link for the extra 15k MR or your Aspire referral link for the extra 20k HH bonus), get approved, and get the card number or a temporary card number, or even get the card overnighted to use on the hotel bill.
Amex sometimes offers a temporary card number immediately after approval that you can write down/screen cap for use. There’s also a hidden feature in your Amex online account, once you’ve added your new card, that lets you get the card number and temporary CID for a newly approved card that’s still in transit:
https://www.reddit.com/r/churning/comments/904w5b/comment/e2oclw2?st=JPO9M59W&sh=8762333f
However, there may be a low credit limit on the temporary card number, as
@miztressuz experienced:
https://www.disboards.com/threads/i-love-credit-cards-so-much.3528202/page-2162#post-59621012 In the end, I believe
@miztressuz was able to get Amex to overnight the card to her husband to use on a contemporaneous hotel stay.
I know you kind of suggested your husband doesn’t want to apply for credit cards, but it’d be such a waste if he’s not getting the best return in rewards from a really large hotel expense, i.e., 1 MR/$1 on the Platinum or at least 14 HH/$1 for Hilton charges on the Hilton Aspire. Not to mention that the Hilton Aspire comes with automatic Diamond status, which gets him another 20 HH/$1 (10 points/$ base earn + 10 points/$ elite bonus) because of his elite status.
I think the Aspire was possibly on the table for DH, anyway, and now would be a great time to get it if you can appeal to his rational business side. I’d imagine this weekend’s hotel bill would more than hit the $4k MSR, so you’d get the 150k HH signup bonus and a whole lot of HH points from the stays.
Also, remember the Aspire comes with a $250 airline fee credit that can be used every calendar year (including on AA, Delta, and Southwest gift cards in certain denominations per transaction — let us know if you need help using up this benefit on your or hopefully DH’s cards), so there’s still 2 weeks to dip this benefit in 2018, before it resets for another $250 in 2019.