The issue is that individual experiences vary so much that it is really difficult to give you a concrete answer other than to prepare for every situation.
I had my N400 interview last Friday, with a pending I-751. My husband came along with me. The IO didn't need him to come inside for the interview so he just waited in the USCIS lobby. Before the interview I prepared an updated binder for all the new stuff since filing for citizenship: 2022 taxes, updated insurance, current bank statements, recent vet bills. However, we had submitted a pretty large binder for both I-751 and N-400, so she said she didn't need any more documentation from us. So all in all if my husband hadn't taken a day off work I think I would have been absolutely fine, though we did enjoy a really nice sushi lunch together post-interview and day home.
On the other hand, you read stories about IOs wanting to interview spouses or refusing to proceed if both partners aren't there. I'd probably play it safe and have your wife attend if at all possible.