Do I go back early to help set up?

My husband decided to take a step back from his sister and her husband. They live at my MILs but are in the process of moving into a house. It’s not that we’re not completely going no contact, just not being around a ton.

This weekend is my nephews baptism, I’m the god mother and we’re staying the weekend at my MILs. Plan was to drive back on Friday night.

My sister texted me Monday “when will you be back? I could use some help with (nephew) and getting ready for the party?” Then before I could respond my mom goes “could you take the train mid-week? We need you lol!” She previously asked if my husband would come back Thursday night so I could help her find a dress for the baptism. My sister goes “yes I need your help haha” I texted back “let me talk to (husband)”

He works remote on Fridays but recently revealed that he’s the road block on a big work project so will need to work a ton including weekends. I’m staying from the baptism to the weekend after because we’re taking my mom away for her birthday. I’m also missing his birthday(1st married) because it’s mid-week and he told me to go to the birthday trip as he’ll be working.

I tell him last night how my sister asked me to come back early to help. He says “your sister can be a bit unreasonable but then again so can mine” then said “You’ll have the desserts your making for the baptism and a weeks worth of clothes you can’t take the train with all that. I’m laying it out there on the table, we can go back Thursday night if you want”

I haven’t decided anything but wondering what you’d do? Part of me feels like I should go help my sister but another part of me doesn’t want to force my husband to have to work at his mom’s where his sister will be all day.