I sort of have a similar problem in that I don't own a laptop. If I go anywhere to write, I have to write freehand also. I always end up w/ about 800 words; never anything more. There's probably a different thinking process involved with freehand.
If you can't change the situation, don't worry about reaching 50K. Reaching 20K is still more than what most people do in a month. I saw in the forum that some nano-ers were in last year's contest and didn't reach 50K. They "re-working" their novel from last year in this year's contest.