five pounds of grain takes up 4qts. so with water added, a 20lb grain bill would take up 16 qts, and add in strike water at 1.5 qts/lb gives you a total of 30qts water plus your 16 for the grain and you have 46 qts.
I can make 10 gal batch of pale ale in my cooler, at 1.056 og and mine is much smaller than 62qts. not sure exactly how big mine is, but its enough for what I need.
your 1/4 bbl should be big enough too. I use a 20qt stock pot for my hlt. Occasionally I need more water, so I use 2 pots in those cases.
My wife is like a well crafted beer...bitter, yet sweet enough to balance perfectly!