Needless to say, there a lot of people with that kind of gearing who aren't anywhere near that strong. If the bottom gear isn't low enough, the only way to climb a long hill is at a painfully slow cadence. Or to walk. Unless you can maintain at least 22 MPH, you still need a triple. If you can really manage 28 MPH, go for the corncob freewheel.
Individual preference plays a role, of course.
Even with the optimum gearing, getting to the top of the hill is still work. Total weight, pounds Wind resistance and other friction are neglected, a pretty good approximation when climbing steep grades, where most of the energy goes into simply overcoming gravity. All friction except air resistance is neglected, but this is a reasonable approximation for speeds above about 15 MPH, with the rider in the crouched position on the drop bars. At lower speeds the rolling resistance of the tires becomes significant. Frank Rowland Whitt and David Gordon Wilson, Bicycling Science , MIT Press.