Okay, after some tinkering I think I found a temporary solution to the comments problem. I have installed Haloscan comments, which, unlike MT's comments, are hosted somewhere else. They don't affect my current server's processes or suck away my bandwidth.

However, Haloscan does not officially support MT, so like I said, I had to tinker. I'm not sure the comments will work seamlessly, so I'm not guaranteeing anything.

Also, note that none of these comments will be saved once I migrate the site over to its new home, so don't write your masterpiece on these boards.

But, if this works, I figure it will provide at least some measure of relief until the migration is complete.