The short answer is no. If you're going to be carrying that much, you should get a bike set up for it or modify your Trek. Most road bikes don't have rear rack eyelets, and carrying anything but the lightest loads on a clamp-on seatpost rack is miserable(trust me). How will the bag attach to the front of the bike? do you mean a handlebar bag or are you going to swap out the front fork for one that holds a rack?
You could also take a trailer, but the trailer itself is very heavy. You don't want to load one up too much because of the lateral stress it puts on your frame- you need to be sure your rear triangle is up to the task.
I think your best options are looking for a bike with rear rack eyelets (felt makes a few, among other companies), and reducing the amount of stuff you're hauling until it fits. It's always more pleasant to carry less, anyway. backpackinglight.com and the ultralightbiking yahoo group are great resources. On the ultralightbiking yahoo group, there's a trip report from a guy who went across the US in around 3 weeks (camping, too) with all of his stuff in a bag behind his seat- it shows that you can definitely constrain your gear to a rear rack.