Based on my past forced-induction vehicles, lifespan is inversely proportional to the amount of boost you run. More boost = shorter lifespan unless you spend a lot of money upgrading internals. Good fuel with sufficient octane, watching air fuel ratios, keep temps in check, and limiting detonation are also essential. I've had turbo cars last almost 500k miles and still ran well. I've also had them last 2 runs at the track because wastegate didn't work properly.
Obviously if you ride the P!$$ out of it, that can reduce lifespan too. I can't see why a boosted R3 couldn't run 60-100k miles easy if not running a lot of boost and proper maintenance.
The more I think about this, the more I want to do it. Just need to find someone local to do it. I just don't have the time and place to do it anymore myself.