Hyde is ad-libbing his way to an evil plan here. He tends to get so focused on whatever task is at hand that he doesn't really think what to do past the moment he finishes it. It's actually pretty forward-thinking of him to even decide: "Once I get free, I'm going to the Bazaar." He may very well be forming this new plan of "maybe I'll seize control forever and force Jekyll to be my mind slave and go grocery shopping and pay taxes and stuff for me" in the same instant that he's saying it out loud . . . but that doesn't make it any less formidable a threat. Once Hyde realizes that he doesn't HAVE to ever go home, why would he?
(Are there stories where Hyde permanently gains control over Jekyll's life? League of Extraordinary Gentleman comes to mind, or other versions that veer close to Hulk territory. But I feel like most adaptations end up killing Hyde before he gets to that point . . .)