See You Sleep,
"This is a Alpha/Beta/WIP mod, it needs testing so I don't recommend to use it on your main saves"
"Last updated at 21:58, 13 Feb 2013"
Naa probably not.
Saturalia Xmas in Skyrim,
This is actually pretty cute, but is too big to be added without having to tweak other stuff. (and many would find it tacky) Plus it's not single day or season event, it adds all those Xmasy changes and they stay until you install a remover. So nope, not a good fit for this pack.
The Xmas Lanterns mod looks very nice, I like colorful things, I'd like to see it with different ENBs. It sounds perfectly safe to install, but I can't say if it's appropriate to include in PM.