Really, guys. Notes - its very important part of each tasks. Please make it free! :)
Thank you for your suggestion and your request in the Votebox. Unfortunately, we can't offer many features for free especially those that mostly affect storage space and notes have no length limitation and allow you to upload files (up to 20 MB per file).
You're welcome to sign up for Todoist Premium and you would have access to many more great features :)