I wouldn't need much land except I would like to heat with wood. Having a few acres of trees to coppice would be beneficial. As to isolation, I currently live in the heart of a city and go weeks without speaking to another soul.
If I might humbly suggest from personal experience in my youth, the Hudson Valley region in NY state and Sussex and Warren counties in NJ are great places to enjoy solitude and nature. I attended retreats on some campgrounds in these areas and also spent long stretches of summer with family residing in these regions. The local communities offer a close neighborhood feel without being overbearing and I remember feeling rejuvenated after visits, even as a child. Also, I think my love of watching birds came from these times. I can still remember hearing the croak of ravens, seeing baby owls, identifying so many types of birds, and watching different raptors soar in the air or perch in a tree while hunting. Nothing has matched the diversity of birds that I saw in that region, and I still manage to incorporate at least one bird watching experience every time I make a visit to family in the area. During my visit over the holidays, I spotted a bald eagle soaring overhead. I actually got emotional as I praised the Lord for allowing me to see such natural beauty.