Sleepovers for Newborn

First off, Happy Thanksgiving! 🦃 So we are going to my MIL's for dinner today and she texted me this morning about having my daughter spend the night there so that my husband and I could get some real sleep. I love my MIL but I just think it's too soon for this. My LO will be 6 weeks on Saturday, she's formula fed but we only have 6 bottles that we rotate through so my MIL would have to wash/sterilize them repeatedly. They have well water too. I welcome the gesture and good night of sleep but I just think it's entirely too soon for me to be shipping my newborn off to Nana's house. I haven't said anything to my husband yet because I'm letting him sleep and she only texted me. Opinions?! When would you let your LO spend the night somewhere else??