Is it sometimes appropriate to use past tense when stating a fact?
Solution 1:
I would go with the former, with matched past tenses. The sentence implies an evaluation by you of the distance to school, and that occurred in the past. With the latter, it sounds like you didn't go to school in the past because of an evaluation of the distance occurring at the present time, which is mildly confusing. People will understand it, and native speakers might even say it, but it doesn't sound as good.