How do you handle schedule interruptions?

For 1.5 weeks, I had my baby on a schedule and he went down awake and slept through the night without any true crying (yay!). Then Easter weekend meant visiting family, pushed wake windows, and driving home at bedtime.

Yesterday, naps were off and we had a false start despite having a good last wake window and going down awake initially. We then bounced back to sleep because we felt it was the schedule making him off. Today, family was visiting before bedtime, we skipped bath, but he still went down later than I'd hoped and wouldn't settle, so we bounced to sleep because he was 30 minutes past wake window by then. Another false start.

Clearly he has the skills to put himself to sleep when timing's right, so am I wrong to help him to sleep when the schedule's off? I've read that you can't sleep train out of a bad schedule, so it feels cruel to try and let him CIO when I know he's overtired. Or am I creating a bad sleep association?

And then are you guys making these allowances or strictly adhering to the schedule, even if it means visiting with people less? This is our first LO, so I feel like we're still navigating from our life before and just now learning the importance of a schedule.