That same year, Rees portrayed Fred Hollywell in A Christmas Carol, which he also narrated, starring George C. Scott as Scrooge.

From 1989 to 1993, he appeared intermittently on the long-running American television series Cheers as the English business tycoon Robin Colcord, a love interest for Rebecca Howe (Kirstie Alley).

[7] From November 2004 to October 2007, Rees was artistic director of the Williamstown Theatre Festival, only the fourth person to hold the post in its half-century history.

In 2014, Rees directed Dog and Pony, a musical written by Rick Elice and Michael Patrick Walker, which had its world premiere at the Old Globe Theatre in San Diego.

His last role was as Anton Schell in the musical version of The Visit, opposite Chita Rivera, which opened on Broadway on 23 April 2015 and closed on 14 June 2015.

[12] Rees was to have directed a new musical written by Elice and Will Van Dyke, Magnificent Climb, in the fall of 2016 at MCC Theater in New York City.

[14] Rees married his partner of 33 years, playwright Rick Elice, in 2011, shortly after same-sex marriage in New York was legalised.

[4] In October 2017, Elice wrote a memoir of his life with Rees, entitled Finding Roger: An Improbably Theatrical Love Story.

[19] After a diagnosis of brain cancer in October 2014, Rees focused his energy on his commitment to playing opposite Chita Rivera on Broadway in The Visit, the final musical written by John Kander and Fred Ebb.

While undergoing two brain surgeries, two courses of radiation and ongoing chemotherapy, Rees managed to rehearse, preview and open in The Visit on 23 April 2015.