I believe McCain would win this contest handily.
The south would remain loyal to the GOP. Clinton would not play well in the south. Warner may help to improve the popular vote for the Democrats in the south, but enough to win states, not even Virginia, as Warner is the VP candidate, not the candidate for President.
The west, including the southwest, goes to McCain. He goes over well in those regions.
McCain picks up the swing states of Oregon and Wisconsin.
The election is decided largely on McCain's national security credentials.
The minor parties would be peripheral players only, and would not impact the election results, drawing only a very, very small percentage of the popoular vote.
McCain/Huckabee 303
Clinton/Warner 235
I think McCain would also win NH and have a shot in MN, MI, and PA