Can I get a Tourist (L) single-entry visa 6-months ahead of entry?

I am a UK resident.
I am planning a 6-month vacation in 2018 with the final leg of my journey being a 14-day tour of China, starting in Beijing and leaving from Shanghai.
My online research is leading me to believe I can only apply for the visa 3-months ahead of entry. Given the duration of my trip, that will not be feasible - I will be in New Zealand during that time.
I would appreciate your advice and detailed options (if there are any?).
Thank you in advance.