I've currently got 12 1/2 and my 16yo has 8 1/2 (we share a Dawes Kingpin that's been in bits for months). Losing my storage space last year, at least until Covid's under more control, has meant a re-evaluation of how many we can actually accommodate. My son's got a team bike coming as well with no space whatsoever at the moment to fit them all in..
I'll be selling 3-4 bikes this year. Which is what I did last year, but then bought 4 more

. The Raleigh Superbe I've been working on will go, as will either my Wilier Montegrappa or Raleigh SP Race as they would both be commuter bikes. The Giant Trinity TT bike I lent out last February
will come back to be sold. Then I've to decide whether to keep the NeilPryde Nazare we have on the smart turbo or sell it; the probability is it'll stay since that makes things easier logistically. Oh, and my Fuji Track bike's off somewhere as a team loaner.
So I'll have 8-ish left. Unless I buy more
