Our rescue mystery boy, any ideas

Bodie is about 65 pounds, He has a GSD carriage, slick coated (not exactly like lab “layered” fur) but loves the cold and snow. He has grown into his ears, is very intelligent, excellent vocabulary. Can be a tad stubborn but that is usually only outdoors when confronted with wildlife or cats (someone suggested some sort of sight hound). I also note that he has pretty well developed scent talents.
Not much of a barker (except at same wildlife and cats) but does have a fine repertoire of songs akin to a husky. Very high energy at play times but not destructive or hyper in the home.
A great all-around boy who we’ll adore forever no matter what his lineage, but I’m curious what others think they see in there! Thanks!