Incomplete:
1 sci-fantasy YA that I intend to go back to as soon as I finish the first draft of book 2 of my urban fantasy YA series. (probably early 2017 - around 35k written)
1 UF YA that I want to go back to after I finish both the above and books 3/4 of my series. (so only in 2018 - around 20k written but needs a full rewrite)
1 weird time-travel/fantasy/comedy/adventure YA thing that I'd like to rework as middle grade eventually. (no idea when though - around 20k written)
Complete:
I have three completed middle grade novels in Portuguese that I'm never going back to because I switched over to writing for English language markets, and they're very much 'local flavor' and not really translatable.
I have two more completed middle grades that I'd like to get back to and rewrite at some point. One of them was planned as a trilogy, and has potential to be upped to YA. On the 'back-burner' at present, simmering away. (for the trilogy, perhaps around 2018/19; the other, who knows?)
I have a trunked novel that was first written as YA and then rewritten as middle grade. I don't think it's worth fixing – it's too deeply flawed – but I learnt a lot about plot tightening in the process of moving from YA to MG, so it was worth the time I spent on it! Also, I've already stolen a few ideas/characters from it, so am slowly picking it clean of things I liked in it.
NOTE: Yes, I really do plan my writing that far out. Writing, for me, is the long game, so I'm happy to put things aside and say, 'see you in a year'.