I did it for almost 3 months as a 29 on my titans (had 2 at the time). Boots just would not drop for me, I was only able to get to 30 once IB sold level 30 boots. And even after that, I still didn't get VoG boots until after Crota came out. It was definitely a big challenge though. I know personally I had a very hard time trying to kill the minotaur with the relic while it outleveled me.