Not sure about appealing. There may be a chance to quash on unreasonable delay of trial, but I can't say for sure at this point. How long ago did you request the trial? Was it January of this year?
If they try to corner you and tell you that they're moving the date again, politely tell them "no you're not," and then strenuously object to the JP, telling them that you have sacrificed time off work (again) and the Crown has failed in its obligations to prepare for trial at the required time.
Now, as for the charge you're facing, where was the officer when he observed you allegedly disobey the amber light? (Behind, other side of the intersection, cross-traffic?) Have you made a disclosure request yet?
Your strategy for the trial should be workable, especially if the officer was not directly behind you when you proceeded through the amber light. Just state, as you were going to, that you were travelling at what you believed was a reasonable and prudent speed for the road conditions given your driving experience, you noticed the amber light, and reached the conclusion that the vehicle could not be stopped safely, so you proceeded with caution.
Write down section 144 (15) of the Highway Traffic Act, available here, if you haven't already:
http://www.ontariohighwaytrafficact.com/topic76.html
Quote it in court; ask the officer if he agrees that this is the section he charged you under. If he was not directly following you, then ask him: Did you drive over the section of road I was on to verify its exact conditions? How can you be sure that I would have been able to safely stop my vehicle? How close could I have been to the intersection to have safely stopped it? Just because he was at the same intersection does not mean that the part he was on had exactly the same level of traction (or lack thereof) that yours did. Stick to your story, show that you complied with the law and then ask for the charge to be dismissed.