You can adjust the encoding of the file with transcode to make the final file smaller so you can fit more vids on a single disk. Read the man page for more details

# Added "-Z 352,fast" to test compression
# Added "-G .7" lighten with compression

transcode -i "$FILE" -y ffmpeg --export_prof dvd-ntsc --export_asr 2 -Z 352,fast -G 0.7 -o movie -D0 -s2 -m movie.ac3 -J modfps=clonetype=3 --export_fps 29.97