colt, it's perfectly possible to get it a lot faster than 29 days even though the level for a required quest has changed, because now we have many buffs to help, daily quests and daily bonus. however, i believe it's nearly impossible to get there without spending nuggets. why? because even with a really wise management of your energy and health, you only have a certain amount of energy without having to refill; and for that, you need either bond buffs (20% every 10 minutes won't help) or nugget refill in worlds where you can do that. premium automation and energy are extremely useful, but that also costs nuggets. now, remember we are talking about 29 days or faster, starting from level 1, so there is no chance a player would be able to rack up enough bonds to fund the cost of buffs (energy, health, instructions).
bottomline, a really crazy & skilled player, willing to sacrifice sleep and end up with a much lighter wallet, could do it in a week if they reaaaaaally wanted it. one not so skilled but equally willing could do it in 2 weeks. i don't know many players who can do it, and the few who can, don't want to. but, they will need to spend nuggets heavily.
*edit*: she started the character when she said she did. she also quit for a weekend so, if you substract those 2 days when she didn't log in, she actually got her gg in 27 days. you can track her character via westforts (nancy callahan, world 11), since part of her leveling was done through battles. she did the same a year later, this time using the help of buffs (no shop bonds existed yet), during the first 50 levels when she didn't use nuggets, with rick perry on world 12. with full premium & shop buffs, the higher level is nothing but a pebble on the road for someone who wants to get the gg in less than a month.