First off, you must be speaking miniDV tapes - yes?

Some Math with easily doing 2 hours (120 minutes) to a DVD:

1 x 1miniDV tape = 1 hour ( yeah?)

20 miniDV tapes = 20 Hours

2hours = 1 DVD

20 Hours = 10 DVDs

So, that's the Math on the DVD side of things.

OK, why not TRY a straight: miniDV FOLDER >> DVDA ?

I also have/had a copy of DVDShrink. Theoretically, once you have Prepared a DVD from 2 miniDV tape Folders, within DVDA, and IF you got into trouble with size, passing this DVD structure through DVD Shrink would smash it further down.

Now IF you had had a DVD recorder!!!!

Grazie