Horror novel set in winter featuring kids

Read this years ago and it seems like a "It" rip off whenever I think of it. Features a group of kids fending off a monster during a hard winter in a US town somewhere in New Jersey or Vermont. They run into this strange fat kid whose bullied and help him out. They meet his mother who is a "bombshell" looks wise and find out the old mansion in town is the new kid's home.

This isn't a YA fiction as it's seems like the author is a mix of Stephen King and Brian Keene but fails both departments. The author can't decide if he wants to be vulgar or a bit more tame in writing about certain situations. I'm not wanting to buy the book but settle my mind by knowing the title and author. Found it searching Amazon's old Listmania feature and picked it up at a library soon after.

SPOILER

Come to find out the Mother of the the weird fat kid is actually some kind of banshee/succubus and the son is maturing to become an Incubus(?) hybrid near the climax.

Had a decent plot and some nice scares but for the life of me it felt like the guy read too much Edward Lee and tried to put a Stephen King spin to the story. It was an 2/5 star book but the cover was one from 2006-10 where first time fantasy/horror paperbacks were eye-catching as hell.