I (along with some extended family) are taking a cruise this coming July in and out of Southampton. My parents and I are flying into Heathrow in advance of the cruise, and plan on taking the bus (most likely National Express) from the airport to Southampton, where we will be staying prior to the cruise. We've done this before, however it's been several years, and the last time we did so it wasn't peak summer travel season. The last time we purchased tickets when we arrived at the bus terminal (between Terminals 2 and 3), but I believe we are arriving into Terminal 5 this time.
I guess I'm worried about buses being busy/full and having to wait while being jet lagged, as we will be flying from Vancouver (a 9+ hour flight).