I would likely feel calm and at peace. Love the wilderness and solitude. Hopefully thankful for life; but one can't always rely on being aware enough of your relative circumstance at that moment to feel that. Happy ? Perhaps. I would say content would be better word (still working on what happiness actually is in my middle age). Anxious/Nervous not typically. The only exception is if I had solo scrambled up a difficult route to get to this high altitude lake and I was still there at sunset and needed to down climb with a head torch.
Well you're out there a lot it seems.... so i'm guessing you like it more than most.