I think you can achieve this by first reversing the sorting order (filter posts_orderby), and then reversing the selected posts (filter the_posts). By doing this double reverse you circumvent the problem that you have to know the number of posts your query will return before you execute the query.
Keep in mind that WordPress (I think via the canonical rewriter) will remove the /page/1 part of your URL, so you should prevent this from happening. Also sticky posts might need attention. See the code for WP_Query::get_posts() for hooks to change the post query.