My Advice is not to get settled into the Instructor role for too long anyway! If you stick at it too long Charter companies unfortunately tend to think of you inferior and lacking experience.
I found that if you head north with too many hours they deem you overqualified or less likely to stick around and do your mandatory 2 or 3 years service with them.
I did find that most companies that I I spoke to wanted Pilots with a CPL with an instrument rating with 200-300 hours.