Here's a warm 3 piece PJ set for winter.
This comes with a long sleeve pajama top, long pants and a pair of blue shorts for when it's not as chilly. The top has modern running forward Sonic on a light/dark blue wide stripe background. It has red collar and cuffs, with blue sleeves. The pants are a lighter blue, with scattered modern Sonic poses in a pattern that's not too busy. It has red ankle cuffs. The shorts appear to be plain, without any Sonic design on them. The material here is supposed to be mostly cotton.
With a really large Sonic on the top, and cool pattern for the pants, this is a nice set. It's likely to be 'big kids' size so it may fit some...but not all. This is a fall 2019 item, and should be about 25 dollars when you find it. It may be either Target or Amazon item.