G Expedition belongs to "G Adventures" which is a small group tour company with tours all over the world. Therefore if you are a single traveller you could choose to share a room instead of paying a single supplement.
The crew is amazing and guest satisfaction is bigger than holding to a certain itinerary.
I travelled with the tour called "Spirit of Shackelton" from Ushuaia to Falkland Islands (2 days), South Georgia (4 days) and Antartic Peninsula (5 days). Beforehand only this number was clear, but not where we will make landfall. And the crew made really the best afford to make the most landings as possible and we even made detours on the ship to follow a blow of a whale.
The cabin was great and very spacious in compare to other (much bigger) ships I've travelled, altough the shower was very small. But a little secret I learned; as there is a Sauna; there is also a much bigger shower right there. So while I used the shower in my cabin, my room mate used the other one.