It does grow quite a bit. Sometimes I go through the whole file and take out things which I've finished. I haven't found this to be much of a problem.

My problem is that I lose track of where all of my todo files are; I work on too many (client) projects to keep everything in a single file.

Luckily, over time todos tend to become todon'ts, so losing track of the old ones isn't generally a problem.

Yes