On long-haul, you can usually find out the gate number something like 90 minutes ahead, sometimes more. You may have to ask, but I've always found the information willingly given if it's available.

Remember that there are two sets of lifts that come up from the transit, but only one set of lifts will go down to the walkway at -4. So don't panic if you find that the first lifts you come to don't go down there. The relevant walkways thread probably identifies which lifts they are; I can't remember off the top of my head.