Hi there Michele! The Main Street Electric Parade (MSEP) is my favorite parade at any of the parks Wlat Disney World parks! I remember watching the parade when I was a child and I made a special trip this past summer just to make sure to catch it. I am so glad that they have extended it! Hopefully, it will stay for a while so when we make a trip back to the Magic Kingdom, we'll be able to watch it again!
If I am not mistaken, the parade runs around twenty minutes. I remember because I was recording it and I only had enough video for eighteen minutes so I had to stop recording between certain floats to meet the eighteen minutes. Remember to bring your camera and extra media cards or film.
The parade start time for MSEP is typically at 7:00pm but always check the Times Guide for parade dates and times, which is available at the park entrance, guest relations and most merchandise locations. Artist Point is open until 9:30pm so if you try to change to a later reservation (407) WDW-DINE and don't get stuck in the crowds you should be able to make it. My advice would be to watch the parade where it starts in Frontierland then get on the Walt Disney World Railroad to avoid the crowds on Main Street USA exit the park and take a boat to Wilderness Lodge. The transportation system at Walt Disney World is very good but, there are times (specially when you need to get somewhere quick) that it may bog down.
You didn't mention which day you have the reservation and for what time so I have listed the parade dates with times below from the Disney Calendar just to make sure you know when they are planning to have it.
February 12 7:00pm
February 14 7:00pm
February 17 7:00pm
I hope you and your family have a Magical Time and enjoy the parade and dinner!