Just ... how? It takes a total of 2,950,000 XP. With the full legend bonus you make 6xp/second, So 136 hours. However, you there's only been ... 3 weeks of the bonus so far and after you hit that cap you're only earning 3XP/second.
So ... you could work through all three weeks of legend bonus with 62 hours of survival time. That would get you to 1,350,000 XP putting you at level 46. After that you'd need 1,600,000 XP, without the bonus, so 148 more hours of survival time.
So, 210 hours? In three weeks?
Obviously, this doesn't count the +50XP per kill, or damage, or +900XP for a win, but holy crap guys. That's some commitment.