I've seen this made up as a nightie, which could be fun.
I've also always wanted to make this dress up as a nightie in a soft knit. Maybe the top in a knit would be cute with some matching knit boxers.
Could use one of cami patterns from Otto for the top and the Jazz pants pattern for the bottom of that one.
If I get to it, I'll make up some sleepwear for DD as well. She's covered for the minute, but is growing like a bean. I'm fairly sure she'll be OK for summer, but winter PJs will be another story. Of course, buying clothes for her is easy and inexpensive, so that's always an option.
AND, last but not least, I'll be sewing some boxers for DH. I was supposed to get to them as part of his Christmas present, but that's not going to happen, so I'll be doing those in January. Hopefully, once I've got the pattern and construction ironed out, I'll be able to sew him up a few pairs. I've got a few lengths of suitable fabric here and it would be good to use it all up. (2 of the pieces are in the first basket of target fabrics).