Knowledge of 3000 characters in Chinese is enough to read about 99% of text. Many words use two characters. Then there are Chengyu which are generally 4 characters and are derived from an old story. 850 characters would definitely be enough to communicate, and word creation by combining characters together is more flexible than English. Since every character can be a word, it's a little trickier to define what 850 words would mean, as 850 characters gets you thousands more words.

Just use a word frequency table and take the top 1000, power through memorizing them, and then learn some basic grammar

I would love to see this in Dutch and many other languages!