Talking form a perspective of someone who worked at Google and one other similar company that shell remain nameless... as well as simply looking at places like Github where people tend to post projects they are working on: I don't know of any Github project that would be even in the size range to cause any discomfort for a laptop user.
Even when it comes to the larger projects: I have multiple checkouts of GCC and Linux kernel on my laptop, and when I run du their existence doesn't even register in the first dozen results... Of course, proprietary projects tend to be on a bigger side due to putting a lot of not-strictly code-related stuff in a repository, but still... it would have to be billions LoC big to be prohibitively big for a typical laptop.
Even when it comes to the larger projects: I have multiple checkouts of GCC and Linux kernel on my laptop, and when I run du their existence doesn't even register in the first dozen results... Of course, proprietary projects tend to be on a bigger side due to putting a lot of not-strictly code-related stuff in a repository, but still... it would have to be billions LoC big to be prohibitively big for a typical laptop.