When you feel hard to update blog, then you do not have to update, just leave as it was. Do not confuse and you think that you must to update your blog, I suggest you don't have to update if you feel you don't want to update even if your blog don't update so long.
So when you think that the time was right to update, then you can update it your blog, because if you trying to update which you don't have spirit to update then you may get confuse to write something word, even it was 50 word. Just trying your soul when you want to update it.