(Lol, this made me randomly understand the phrase "Hail Mary", ha, as in hailing a cab. 
)
I am certainly not a todo guru, unless you count having tried every technique over the years, grain of salt...
I think there are a lot of good ideas in this thread. One you mentioned is breaking each todo into it's own note. Now that there is the Kanban Plugin, I plan to use this technique for managing larger projects. I have used Trello in this way for years and this will supersede that.
My current todo system involves creating a daily note (shoutout to the new Template Plugin) that is named based on the date. I use this note to track / log other things, but the bulk of it is my todos, broken into categories.
Each morning I create this new note and then copy over my entire todo list from the day before. I delete things that were completed and add new things to appropriate sections. My sections are GTD-style, so they are grouped more by where / what mindset I am in (Errands, Focus, etc). Then I set 1 or 2 things as "must be done today" (the fewer and more realistic the better).
While it seems like it would be annoying to have to "remake" the list each day, I find that I am quicker to toss out things I am never going to get around to without feeling bad, and yet I feel ok with keeping long term things I will need to get to on there.
Another nice thing is that the Note Tabs plugin just added a way to see number of checklist items done inside a note, which is really nice for a "single note" todo list.
(This also ended up with a positive side effect – any todo that is on-going generally links to another note with more details, so those end up with a "Backlink" to my daily note. This lets me see how long and when I worked on something. )