Best way to move 2 iMovie projects to 1 iDVD project?

Question

I am in a last minute bind and I was hoping I could get some help! I am making a DVD for my wedding reception that is NEXT weekend. ah! Anyway...here is what I have done:
1. Created three slideshows w/ KB effects in iPhoto and exported them to quicktime movies. (Question on that if anyone knows - only had three quality levels for that creation, and I chose the highest. Is this the best way to turn these slideshows into movies for eventual incorporation into a DVD??)
2. Imported all three slideshow movies into iMovie because I want them to play back to back (and found iDVD can't set it up that way) - added title slides between them & stitched them together in their entirity. Now I have one, big movie creation in iMovie that I want to be a feature on my DVD
3. ALSO created an interview/tour video of our home and town to show at the reception. It contains multiple clips (over 120 edited) from a video camera, extracted audio from the video clips (for some), imported song files for background music, transitions, titles, etc. Now I have one really nice, almost 25 minute video video that I want to be a feature on my DVD.
What I want to do:
I want both of the movie creations I just described to be on my DVD. (I am planning on doing a third, if it fits & I have time, and I can do the same thing with that based on whatever advice I get.) The DVD will be really simple - just a single title on the main screen of the DVD for each movie b/c they will be played at different times during the reception.
My questions/concerns:
I looked at my options for getting my creation onto a DVD - here is what I found:
1. I can share straight to iDVD - but it appears I can only do that for a single movie per DVD project. When I went to share the second movie, it asked me if I wanted to save my original DVD project before making a new one. So it doesn't seem like I can "share" multiple movies to the same DVD project. Also, when you do this - what is really happening?? It didn't take very long, so I know it wasn't copying files over. Is it just making links back to the referenced files, and will somehow write a movie when I actually burn the DVD? If so, what then will be my options for creating the movie??
2. From iMovie, I can export a project in a number of ways (to video camera, quicktime, email, web, etc). I am assuming that quicktime gives me the best, but not sure. The PROBLEM is that when I exported my main (25min) video, it was over 5GB!!!!!!! That seems a tad big. I forget the size that a DVD can hold, but it just seems like there should be a better way, and this is too big (maybe not?).
Needs:
As I have stated, this is to be shown at my wedding reception (and maybe parts at the rehearsal dinner). Primarily it is designed for an overhead projector, but obviously it will be watched on TVs/computers at some point.
I am wanting to make sure the video(s) is the best quality I can make it so that it all comes out well. This is my FIRST project, so there are several things I just don't know enough about at this point - learning with this important video, must be crazy!! It looks REALLY good so far, now it is just outputting it so I can show it to the world.
Thanks for ANY pertinent help you can provide, and please, limit responses to the actual things I am asking about as I don't have a lot of time to wade through things trying to 2nd guess & pick what I need. That would be very helpful!!

Answer 1

You can do it in one of two ways (I have done both):
1. Follow the procedure I outlined using Toast Titanium. You don't have all the bells and whistles of iDVD in the final product, but you have a working DVD. And there has been an ongoing issue with encoding in iDVD where the process hangs or slow way down, especially at the audio endoding stage.
2. Start a new iMovie, and then copy and paste the clips and audio from your other iMovies into the new one. I tried importing but could not figure out how to do that or if it is even possible. The process of copy and paste is tedious and problematic, especially with the audio tracks and if anyone else has found a better way, I would really like to know. But this does work, but be prepared to spend some time. But it has the advantage of you being able to pick and choose.