It's most likely possible. I got to Lv23 before getting the Battle Tower, and could've reached 24 if I wanted to. At Lv24, taking on some Lv27 enemies wouldn't be a huge deal, assuming one assigned skill points effectively and used powerful enchanted items.
I also got Lv9 Increase Damage and Increase Magic Damage enchantments, and dual-wielded Brightblade and Tagos' Axe, which gives a HUGE damage boost. So it's definitely possible, but requires a lot more effort than it's worth.
ofcourse its more effort than its worth! so is breaking the current world record high score on a donkey kong arcade machine though... so is climbing everest for that matter. it seems like it would be pretty challenging and now knowing it can be done i will totally have to do it!
see to some of us doing the seemingly impossible is what makes games fun, to others (who i call wankers or worse) the fun is in downloading trainers, beating games in hours, and then bragging to their friends how easy it was. i just want to soundly thrash every aspect of the game before the addon comes out, plus it is the slowest summer in gaming history.