Consider split routes: Elizabeth line to Paddington, then Heathrow Express for the final leg if you need guaranteed speed and minimal intermediate stops.
For late arrivals, verify that your hotel offers a shuttle from Heathrow; otherwise, use the free rail transfer between terminals and local buses to reach accommodations.
From the West End, take the Piccadilly line; estimate around 50 minutes to Terminal 5, and consider traveling off-peak for a more comfortable journey.
Avoid last-minute stress by aiming to arrive at Heathrow two to three hours before departure; select the fastest route available for your time window.