Realistically.

[stillthinking1]

I scored a 139 on a practice test, I know terrible, but I was up until 4am the night before and I was absolutely exhausted half-way through the exam. Prior to taking that practice test, I'd done no type of preparation. So my question is, honestly, is it unreasonable to think that I could score a 162-166 with sufficient test prep?

[kehoema2]

It depends on what you define as "sufficient prep". However, in general I think anyone can score above a 160, even above a 165 if you really truly work your ass off. However, I want to emphasize work hard. You may need a solid 6 months to get up there, but its definitely possible if you keep at it and are smart with your study methods.

[gens1tb]

Can you do it? Most likely.
Will it require more work than you think? Most likely.