This garment, pajama bottom in particular, was made for a giant! The bamboo fabric is rather warm and should be with winter wearables.
I believe PJs should be a very relaxed, comfortable fit, a flowing drape, in no way constrictive and also feel good on the skin, silky is always nice all of which helps one to get ready to sleep. The size chart should be removed, useless, inaccurate, misleading.