SwiftPaws Home can be enlarged up to 300 feet long and can be set up in minutes.
Under ideal conditions (level terrain, short grass) you might be able to stretch the max length some. The limiting factor is the strength of the motor. Some customers have been able to run a course significantly longer than 300 feet.
That said, the size of the course is not pre-determined. You decide how large or small to make it based on these factors and depending on the area you have to play in. You can see a large course setup here on Facebook - note the ideal terrain.
All of the videos you’ve seen are using the same SwiftPaws Home equipment, just setup differently. You can also see more video of actual customers and the courses they have setup here, you'll see both large and small setups: