What is a single bike solution? Seems like an oxymoron.

If I had to do something one bike, It would have to be a titanium frame with disc brakes and massive tire clearance and thru axles (with sliding dropouts)and I would probably buy different wheels. I can get a Paul Fixed Word hub which would solve issues when I would want to run fixed. I would probably want to run ScRAM only because it is wireless so a little easier to take on and off but I dislike their components so I don't know how I would make it work. However this is a dumb idea and I wouldn't do it. I have too many babies I love to death. I will honestly admit that I feel as though I have too many bikes that I really don't want and some bikes I really do want and would like to sell a couple,


If you were doing it get the absolute best bike you can with as many practical and modern features as possible. Go custom from a good reputable builder, get really good reliable parts on it.
Though life just isn't fun with only one bike.