Ortlieb offers a sensible priced repair service. Unsure if that's an option for other people, but for Germans it is for sure, especially if we talk about bicycle side bags.
Field repairs should be done from outside because Ortlieb repairs from inside.
in the first 5 years there is a repair gurantee but if you are on the water this is no option/ solution for your expensive equipment!
so if you see 7vswildepisode 2 some ortlieb packs are more used than the other so the whole equipment was wet after 5 min - with new packs there is in general no problem but they are only certified ip64
It's possible to waterproof the rucksack and your clothing by wrapping in a poncho. Push in front of you whilst swimming or pull with a piece of paracord (Ridge line from your shelter) I've done this and know it works
yes for normal trekking e.g. crossing a river but there is an very important difference if you are on the water or swim with your gear: you lost a lot of your buoyancy
in worst case with a bergans powerframe the whole pack sink to the floor