Turbo Pascal 2.0 had an IDE with compiler and debugger in a binary less than 60kb (if the info I found googling is true). Of course nowhere near the capabilities of modern environments but state of the art at the time.
Turbo Pascal 3.0 had an IDE with compiler and debugger in a binary less than 40kb (if the info I found googling is true).
https://prog21.dadgum.com/116.html