The limit seems to be 1,200,000 without spaces, but I tricked the system. Copying in the chapter blocks me from editing, but it autosaves. When I reload it, it doesn't start crying until I click into the text. Good. It was the last chapter of the 2nd book anyway. Fuck you, Google, I won!
Ah, fair enough. Although, I don't know how you can manage to write drafts single-spaced. Write all mine in 12-point Times font, double spaced. Just easier for me to read and go through at a glance. As a result, my book 1 finished at 150,000 words, 846,000 characters, and 503 pages.
@RiaCorvidiva My formatting is for SH anyway, and it will change when I am converting it with the KDP program, too, so it is totally useless to bother with formatting too deeply. Make the text uniform and that's enough.
I am doing this exactly for uploading it to Amazon, so the rest of the editing is going to be done to streamline it for Kindle and other ebook readers.