How flexible are number-of-pages submission guidelines for conferences? I'd like to submit a paper to a conference in computer science. The conference's submission guidelines state 14 as the maximum number of pages. Should I take it at face value? My paper is 20 pages long (19, if you disregard the bibliography). If I submit it, can I expect an automatic rejection for being too long? If I'm able to cut it down to 14 pages, but the bibliography spills to page 15, will it count as eligible?
None of the CS conferences I have ever submitted to had ever been lenient on page limits. There are often automatic checkers that will not allow you to upload a paper that exceeds the page limits. Conference guidelines are usually very clear and unambiguous, go and read them. Some conferences allow an appendix or a link to additional material that reviewers can read at their discretion. 

Regarding splitting the papers - if you can do so in a clean way, and both parts make sense (tell a compelling narrative, have meaningful results) then sure. Otherwise, expect two rejections.