Lower Gear Inches or HTFU?

After riding the plastic fantastic geared toy all summer I finally went for a reasonable ride on the 'ole Steamroller this afternoon. Probably covered about 25 or so miles with no problems but never really spun out so am going to try a lower gear. Current set up is 48:18 so I've ordered a 19t sprocket. Like the OP I feel I should be loving my ageing knees.

Probably a wise idea if only over the winter months.