Correct, it is indeed true that you do not require a visa if you have a valid work (or study) permit.
Immigration and Refugee Protection Regulations, Part 7, Division 5, 190, 3 (f)
See the link below
http://laws-lois.justice.gc.ca/eng/regulations/sor-2002-227/page-39.html#h-106
Here is a canadavisa forum post about it:
http://www.canadavisa.com/canada-immigration-discussion-board/visa-expired-but-have-valid-work-permit-can-i-reenter-canada-after-visiting-us-t99415.15.html
You can see on that post that many people have done this by both air and land border crossings. The only potential problem could be explaining this section of Canada's immigration law to the check-in assistant or the flight attendant who checks your documents as you board the plane; these people often do not have a clue and may give you a hassle. Have a screenshot of that website on hand in case it is an issue.
I have not done this personally as my TRV is still valid, but many people have.