I wear just a diaper to bed, NorthShore Supreme is my choice for sleep and sometimes I will double up if I have been out drinking and exspect heavy wetting as I sleep.
I've been sleeping in diapers for more than half my life. I usually wear a light t-shirt and Dependeco PUL diaper cover over a thick disposable. I often wear a light pair of gym shorts over my diaper too.
I typically sleep in a T-shirt and a diaper. However, now that the weather has been cooling down, I will probably start wearing kigurumi pajamas over my diaper.