If it is in the show: Sansa, Davos, Thormund, and maybe Lyanna (his strongest noble ally outside his House), with the possibility to add Bran if he reaches Winterfell. (Will Jon deflect to Bran if he reaches his ancestral home? Will the other Lords accept Bran above Jon? Will Meera ever get back to Greywater Watch?)
If it is in the books: well, a lot of things have to happen before we can talk about Jon’s Small Council; but I see Davos in it, of course.