Difficult one. Myself and most of my friends are now retired and I know of none of them who could not afford a BBC License. It is obviously true that some pensioners are on the poverty line, but it is equally true that so are many working people. My vote says get rid of it. But of course the "I've worked hard all my life brigade ..." would make it too difficult for the powers that be to make economically sensible decisions.
(Oh comparing this sort of stuff to the Lords attendance allowances, makes good sound bite stuff, but is of not much significance economically, a quick bit of unscientific googling suggests that getting rid of the House of Lords allowances would give every pensioner about 2 quid.)