3-6 months, or more. Theoretically so. It's better to keep H or L visas, especially the principal applicant. But the dependent applicant has more flexibility on status. According to AC21, if there's no decision on a 485 after 180 days since 485 submission, all EB(1/2/3) 485's can change to similar jobs, either before or after 180 days. However, if you change a job before the 180 days, you don't know when the 485 decision will come, and it's a gambling. It's totally safe if you change a job after 180 days. However, I wish you get your green card soon, earlier than 180 days. With a green card, you can change jobs immediately.