I have no idea why xanic is suggesting recording that way because it's a redundant and dumb idea, so avoid it.
Songjun, however, has given you my answer for me

so I'll just expand a bit on it. Group your instruments into sections (if your RAM can handle it) and then record each group individually. Then, in Audacity it's a simple process of importing the tracks and mixing it all down to a single file.
Of course, the simplest method would be to just get more RAM and save yourself the trouble, but I assume that since you're asking this your budget doesn't allow it at the moment.
Also, notating all of one type of instrument on as few staves as possible is going to help, but it's not really a solution.
Good luck with it!
