If you know somehting is coming up that will impact how you are perceived. Right or wrong, be up front about it. Don't damn the other party telling yourself they shouldn't feel this way. And don't try to sneak it, finding a way or some in the moment excuse. Instead, be very upfront about it and put a workaround in place. Colleagues in town and you have to leave early? Put a calendar invite with your time letting them know and apologize, and then setup some time with each earlier in the day.
You have these three pools to pull from; time, stress, and resources. If you don't have the resources, you're going to pull from one of the other two. Choose how much from each ahead of time, and be upfront about it with yourself, with stakeholders, with the team.