For late arrivals, verify that your hotel offers a shuttle from Heathrow; otherwise

https://www.scribd.com/document/1074920514/Getting-to-Heathrow-from-Gatwick-Easiest-Inter-Airport-Transfers-178501

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.