You can freeze whole ripe avocados but it's not recommended to freeze whole ripe avocados.
When you do freeze whole ripe avocados the avocados turn into a mushy mess and are not very good to eat.
Even when you cut up the Avocado before freezing such as cutting the Avocado into chunks or slices the Avocados still end up being mushy and not very good to eat.
When freezing Avocados you should puree them or mash them up before freezing them to avoid them becoming mushy.
So if you want to freeze Avocados you should puree the Avocados or blend them up and or mash them up and then place them in a freezer safe container or Ziploc or freezer bag.
When frozen and mashed up or pureed the Avocados should last for a year or longer.