Minimum required visa length for travel on RC?

What is the minimum required number of months that a holder of a UK Residence Card must have left on their Residence card before they are allowed entry back into UK at the airports. So for example, will an individual whose Residence card expires in April 2019, be allowed back into the UK if they travelled to an EU country in January or February 2019?
Would a requirement for at least 3 months validity on the RC be applicable at all?

Residence Card is not a passport - there is no stipulation for a minimum validity left on the card.