If already fit in otherways, I think yes, definitely do-able.
It's a matter of training endurance and ability to sit on a bike for extended periods. With just two days back to back, recovery between days 1 and 2 is not critical as there is plenty of time to recover afterwards.
I was told that I couldn't possiby ride my first 100miler without having done at least 75-80 in training. I did 50s, with lots into the wind and did the 100 in 5h 30 riding time, under 6 hours total.