Ride time x distance

IM Brazil is next saturday, and since this will be my first attempt at the distance, doubts are creeping in.
I’ve done my homework on the swim and run, but I’m worried about my bike training. Where I live there are only hilly places to ride, so I’ve done about seven or eight 5:30-6:30 hour rides in training, but that has only averaged 110 to 120 km, never more than this. Because of the hills, my average speed is always in the low 20 km/h. If I were to do the whole 180 km in the hills where I train, it would take me all day, and I don’t think it would be wise.
I’ve done a few 1:00-1:30 hour sessions on the bike trainer with an average speed around 30 km/h, but I just don’t like to be locked up indoors.
Anyway, my question is: does it matter that I haven’t done enough DISTANCE, as long as I’ve put in TIME on the saddle ?