I have two currently, but have had three.
Personally, although I LOVE my Corgi's... two are great... but 3 is just a whole other dynamic, and makes it much more difficult to do anything. Unless you have a huge piece of fenced land, or a huge vehicle, or a lot of family members that will help out when taking them places, two is my limit.
I think I would have as many as I could afford but atm I have one an Im looking for a second one so she can have a playmate as my other 2 dogs are old and dont want to be bothered.Im blessed enough to live on 2 acres way out in the boonies.