I think it should be possible to fix that single led strip, while keeping the headlight water proof. As it just happened on my 2015 T2, I will let y'all know how it went, once I get the time to look at it. Can't imagine it isn't just a wiring or plug issue... and that the actual LED is still fine. After all you're looking at 12V, some copper and an LED driver circuit of sorts.
I agree that it's a joke one should have to replace the entire headlight unit for that, like buying a new car when the gas has run out