A space station that's supposed to be the replacement for the ISS, called Starlab, is (allegedly) going to be launched in one shot on SpaceX's giant Starship rocket. It's half the size of the ISS. Maybe after the lanch they'll make it larger in space? They're trying to avoid the cost of in-space assembly by launching everything in one shot.
"Starlab is a joint venture between the US-based Voyager Space and the European-based multinational aerospace corporation Airbus. The venture is building a large station with a habitable volume equivalent to half the pressurized volume of the International Space Station and will launch the new station no earlier than 2028."
"SpaceX's history of success and reliability led our team to select Starship to orbit Starlab."
Starlab -- with half the volume of the ISS -- will fit inside Starship's payload bay
