You have the same ability to get a house as I do a rare mount.
1. Locate empty plot.
2. Click on sign
3a. Win roll and be happy
3b. Lose roll an repeat steps 1 and 2

There is no situation where you can't get a house. You are free to click on the signs all day and night. Housing is no different then ex mounts. Just keep trying until you get it.

As far as house hunting goes I have plenty of experience. Want to buy some?