I'm playing the style called "fastrifting" lately, which requires me to teleport/vault etc. around and mostly attack elites and elite packs. However, this makes me jump through many GR floors, and I don't want to get trapped at the end of a GR with many monsters attacking me (again. It happened once a few minutes ago, and I was on floor 9.).
Is there a limit on the amount of Greater Rift Floors?
I believe it's the same as the limit on Nephalem Rifts. You get between 1 and 10 floors, depending on the tilesets chosen for your rift. Larger, more open tilesets like Dahlgur Oasis or the large jail tend not to have additional floors down but often have many more mobs than other sets.
You will almost always be able to summon the rift guardian before you find the exit stone, unless you skip too many mobs (the exception used to be the cave tilesets, but most of those were removed from rifts). Though with the changes to elite pack contribution in 2.4, it should be even easier to fill the bar before hitting the end.
