Note: @Joe has created a JavaScript bookmarklet which automates the process described below. It is available at joereddington.com->better-gmail-search.
I discovered this slightly more friendly hack after noticing the URL of the inbox: unread first. After expanding the unread section, you'll notice in the location bar there's a #section_query. With the exception of that one part, it's practically the same as a search result URL.
So, the solution is to first input the search terms and search. Then, in the address bar, replace #search with #section_query.
This will provide you with a search page with the same amount of pages as specified in your settings, without the hassle of creating a filter.
