to the moon and back in a reasonable time
If we're going serious with this... I'd agree with the "to" part. The "back" part, however, had little-to-nothing to do with the Saturn V since the first 2 stages were purely to drive the payload into orbit and 3rd stage was to get it in lunar orbit. By the time of the return journey there was nothing left of the Saturn.
Beyond that, roughly 90% of the mass of each of the first 2 stages was fuel, which, in my mind, makes an argument for either an alternate fuel source to cut down on the overall mass of the launch vehicle rather or to split the journey into two distinct phases, rather than argue for the need for the massive thrust of the Saturn V.
I believe one of the mission types NASA is researching is to undertake a moon mission in two stages. The first stage, carried out in two parts is to get both a lunar vehicle and a crew to the ISS which then becomes a staging platform to begin a second journey to the moon. This would eliminate the need for a single massive launch vehicle capable of propelling a manned module all the way to the moon.