Our companions will be traveling from Manchester to meet us and travel on the Glacier Express. Does anyone have suggestions as to the best route they could take?
The fast way or the interesting way? The fastest and easiest way would be to fly from Manchester to Zürich (direct flights with Swiss) and take the train from the airport to Zermatt.
Geneva is another reasonable airport to fly to if they meet you in Zermatt (Easyjet flies there from Manchester, and may be cheaper than Swiss). Direct train from that airport to Visp, then the narrow-gauge train up to Zermatt. Travel time is about the same as from Zürich. If they meet you at the other end in St Moritz, then Zürich is the only viable option.