I did an intensive course at OFT (Florida) and we flew two sorties each day by default. There were a few days with just one sortie (due to weather), one with no flying (weather again) and two or three days where we did three flights per day, one of which was a night flight (circuits or XC).
Each flight had a block time of two hours, normally. Half an hour brief, an hour in the air, half an hour debrief typically. For XC flights the flight time was increased, and for the solo QXC I think I had a three- or four hour block.
This schedule was perfectly doable, but bear in mind that the only worry on my mind was flying. The apartment was a 10 minute walk from the flight school, and a further 15 minute walk was a strip with restaurants.
I also had all the theory studied beforehand, and passed most of the exams in the first week. Which is good, because from approx. flight 12 onwards we were doing navigation, which required a lot more preparation than circuits or airwork.
So between two and three one-hour flights should be doable daily. As long as you have nothing else on your mind. But don't make the mistake of doing these flights back-to-back. That's just too tiring. Make sure there's at least two hours between flights, where you can relax, digest what you learned, prepare the next flight and so forth.