One or two, I think.
I currently just have one dog, who really truly likes being the only dog.
He doesn't fulfill all my wants in a dog, so I would really love to add a second.
I've had two dogs in the past while living at home, and have fostered a few
dogs with Smiley, and it's definitely doable, but Smiley hates it, and my partner isn't exactly fond of the extra dog around either.
I won't add a second dog unless my partner is totally on board with it, but I'm aiming for about 3-4 years from now. Smiley will also hopefully be a mature dog by then, and maybe a little less greedy/needy for my time.
If I had a huge plot of land, and could spend the majority of my day outdoors with my dogs in tow, I could probably see myself having three, but definitely no desire for more than that, no matter how much space/time I have.