I’m going to assume you don’t mean if left alone, standing there doing actually nothing, other tanks take twice as long to die. Operating under that assumption, without a healer left to their own devices only, yes the other tanks can survive significantly longer staying in the fight. I would put it at around twice as long. Once you go through both frenzied regen charges, you’ve got nothing left to keep you alive. Ursocs isn’t enough to survive anymore, moonfire does not do damage quickly enough to keep you topped up, and barkskins barrier (if you take that talent) is pitifully small.