Will South Carolina non-compete laws hold up in the state of Colorado?

I am a salesman for a tire manufacturer based out of South Carolina. I cannot remember signing a non compete and do not have the paperwork but in my original offer letter it states "Your agreement to sign and be bound by an employee non compete agreement if deemed appropriate by the company on the date you report to work. This agreement would require a commitment not to accept a position with a competitor for a certain period of time should you leave XYZ Company for any reason." I received an offer from the competitor based in Colorado and I was wondering if SC law would hold up in CO? This August will be 5 years with the company and I have tried to move up in the company over the last year. I applied for 5 positions and was interviewed for 4 and was more than qualified for 3 of those positions. I feel like I'm trapped at my current job. With this new job I will not be calling on the same customer base as I will be operating 75-250 miles outside of my current territory. This new position isn't a manufacturer sales rep for which I currently am now but rather a management position on the distribution side rather than the manufacturing side. Another side note, my wife and I have put off growing our family for over a year now as I have been told within the year you should be moving on to another position that would require us to move.