Burning files that are too big for cds

Say I have two video files on my computer. One’s 699mb big (part1 to a movie) and the other is 700mb big (part2). Both are encoded in/as Xvid formats. (Not sure what preposition one uses in those contexts)
Now let’s assume that I use Nero Express to create a SVCD. First of all I do have to get hold of a Xvid plugin for Nero right? Anyway, say I have one, and I then choose ‘part1’. In my head I get the feeling that Nero has to decode the Xvid and then Encode it in some Super VCD format (or did I jump on to the wrong train?), however, wouldn’t the SVCD format of that file become bigger than the Xvid? And if so, as my cds only have a 700mb limit, is it possible that Nero burns as much of part1 as possible and finished it off and then asks me to insert a new cd and continues?!
Please help, and I apologize for this immense post.