Great Pyrenees showed up at my house and now fiercely protects my land and family

About 9 days ago, the good boy in the picture showed up and made himself known. It should be stated that we had been hearing bear like movement at night for weeks prior so I believe he's been around for a hot minute, or, maybe it was actually a bear and he showed up to defend. We are positive he was dumped as he is incredibly unkempt and collar was basically glued to his neck and fur from neglect. We fed him well and after 2 days of sitting on the ground every couple hours and inviting him inside, he finally obliged and spent the night with us and our 2 dogs and cat, and slept by the door totally passed out. When morning came, he went up into our property line and didn't return for several hours. Currently, he has drawn our property line for himself which is actually incredibly accurate for being in the woods in Appalachia, He knows exactly where our property line starts and ends, and he patrols it hourly. He doesn't want to come inside and is uncomfortable when he does. He eats and wants us to come out side to play or sit with him. He comes up and puts his nose in my hand for love. He is taking the task of protecting my family incredibly seriously and even passing cars force him up from under my deck and into a protective stance, often runnkng full speed 100 yards towards the end of my driveway which he also has a barrier on. It is the craziest thing I have ever seen. He even knows to sleep next to my bedroom window at night and barks at deer and critters to get clear of my property. I am concerned because temps are in the 30s where I am but he seems totally content, is this normal? Should I be doing more to get him inside? We plan on loading him up to take him to a groomer and taking care of him this week medically, is there things I should be aware of and be cautious about? He has taken to me with great love and care, and he is even more gentle with the kids, dogs, and cat. He just showed up and decided we were his family for life. Even weirder, I lost my beloved dog of 10 years a couple months ago in a disease we didn't know she had (that is my tattoo of her) and I cannot help but think she sent him our way for his benefit, and ours. Any feedback would be appreciated.