Yes, it's possible.
My daughter (17 and not particularly sporty but likes to cycle) did 120 miles the other day for the first time.
She built up to it with nothing longer than 14 miles at a time. No marathon rides to prep her.
There were regular 4-mile climbs in the Malverns and a nice little 8-mile loop in the roilling hills around our home.
Both of these she did regularly (pretty much daily) for 4 weeks and either at full tilt or at max cadence in a low gear.
To my amazement she got to the end of the 120 miles full of energy, even after sprinting the final 700 metres.
Her average speed was 15.5 mph, which sounds low but there was traffic for the last 30 miles.
Her hands were sore the next day, but that was all.
Go for it!
But make sure the bicycle is sorted, take appropriate spares and maybe consider vaseline or similar in shorts....