Regardless of the time of day you decide to fly, the ticket price will remain around the same. Book flights from Heathrow to Quanzhou as you normally would.
At this time, Cheapflights has noticed price decreases for many domestic flights due to COVID-19. Travel is not necessarily recommended at this time, and flights may be prone to cancellation: please check with local authorities in both Heathrow and Quanzhou for travel alerts, and be sure to review the airline's cancellation policy and travel advisories before booking. For more information, please view our post on what to know about COVID-19 (coronavirus) and travel.
Shenzhen Airlines is one of the carriers that may have flexible change policies. You can use our site to filter for other airlines that may also have this kind of flexibility.