I'm not sure exactly what type of wedding you're planning, but "large" and "extravagant" don't necessarily mean the same thing. Planning a large wedding from another town shouldn't be too much of a problem, assuming you can make at least one trip home. If you wanted something extravagant, that would require multiple meetings with caterers, event planners, florists, etc. then it might get tricky.
I have a friend who planned her entire wedding in one weekend. She knew what church she would be married in. She had a great recommendation (that she trusted) for a caterer, so just met once to pick out the menu. She went to meet with the florist once and ordered everything then. Called a tent company and booked a tent, tables and chairs. I believe she bought the dress and invitations in the town in which she was living. She had a simple and elegant wedding with about 200 guests. I think she may have had to go back one more time to finalise things with the minister (although he was her minister from when she was a child, so he knew her and her family).
I only had a single meeting with each vendor, but I had my wedding in my hometown - so I spread the meetings over a couple of months. Again though, it was a pretty simple wedding.