I am working on a piece that is quite long. I have a demo version that is 20 minutes and 3 Midi tracks. Now I want to build the real version, which will expand on the demo version and be more like 45 minutes long and ~20 tracks. I will need to be able to zip back and forth between the demo and real versions to reference, copy/paste etc. Sections of this piece are to be labeled with Markers. Being so long, there are a lot of sections, so a lot of Markers will be needed. However, since there is no such thing as track- or folder-level markers, I don't want the markers between demo and real to overlap each other as that will just be confusing. Not to mention the constant soloing and muting that would be required. So having the demo tracks and the real tracks just occupy different folders is out. My intended solution then is to move the 3 demo tracks way out to like 45 minutes into the timeline and put its markers there. So the demo and real versions will each have their own sets of markers and they won't overlap.
 
HOWEVER:
1) Dragging those three demo tracks to 45 minutes into the timeline crashes Sonar every time. (btw, at this point, the only data in this project is these three demo tracks - I haven't even started the real version yet, I'm just setting things up now)
2) The piece has dozens of sections, each to have a Marker - because there are two versions, that will be roughly double the number of Markers. I can't figure out a way to display the Markers window vertically and separate from the multidock.
 
Given all this, how would you go about solving this problem? I know the first solution suggested will likely be to just keep two separate projects and have them both open, but I was really hoping to not have to do that, because it's less convenient and a little more work. But if that's the best practice here, so be it. Worth asking.

I can't repro a problem dragging three, long MIDI clips - or groups of non-contiguous clips - out to 45 minutes. Have you tried cut-paste? Or maybe disconnect the outputs of the tracks from whatever soft synths they're referencing, and point them to a hardware port if possible.
 
Personally I would keep the two projects open at the same time, but what you want to do should not be a problem.

how are you dragging in this midi data ? using the browser or windows explorer ?

Ah, ok, the problem is not when I drag the clips out, it's shortly thereafter. I drag the clips out, and everything seems fine. Then I start working and it crashes right away. So I don't think cut-paste will change that.
 
I've started using two separate projects. Not as convenient, but I'll get used to it. However, now I'm reluctant to do something similar in another piece.
 
This other piece is a mash-up of about 50 songs. All the original songs have different tempos. The first step has been to lay down a dummy track for each song I'm using in its own track, as I'm just using little parts of each. How I'm doing this right now is to solo a track, set the tempo to the original song's tempo, and inputting the midi notes at the right tempo. Obviously, if I were to go to another track I've already done, the tempo will now be wrong, because I change it for each song I'm inputting. Right now it's just about getting the raw material into the project, but I'm going to have to figure this out. My idea is to create a marker for each tempo I'm going to be using, each about 5 minutes out. Change the project's tempo at each marker, and drag the songs out to the correct tempo section. In addition, I want markers to delineate workspaces, such as "Raw Materials", "Final piece", whatever. 
 
What I really need for this is something like Excel, where there can be multiple pages within a single worksheet. I'm trying to mimic that with these markers, but now I'm worried that I will be inviting lots of crashes based on my experience with the previously discussed project. Fortunately, this piece is all piano, so I don't have multiple instruments to deal with.
 
If this is confusing, let me explain again:
Bar 1
Marker: FINISHED PIECE
Tempo: Will vary
 
Bar 999
Marker: RAW MATERIALS
 
Bar 1000
Marker: 120 BPM
Tempo: 120
Contains all the songs that were originally 120bpm
 
Bar 2000
Marker: 140 BPM
Contains all the songs that were originally 140 BPM
 
etc....
 
How would you go about this? I definitely do not want to have a separate project for each raw song, because there are about 50 of them, and the finished piece is going to be organically weaving them together, not like a medley where each song gets it's own section and played through. So having a bunch of separate projects would constrict the creative flow I'll need. Ideas?