I have looked into different places in my area which offer different things and what I didn't like is
that they usually offer 2 training sessions per week and each of them takes 1-1,5 hours. this really isn't very much especially when you really want to improve quickly.
If you're willing to pay for it you can probably get that much, but likely not all under one instructor. It's not at all realistic in any sense. Even in University courses where only 3 hours a week or so of instruction time. But if you can afford to train 10 hours a day maybe you can afford to pay to train those 10 hours a day?
Depending on where you are expect to pay $10-20 per hour of instruction in group classes though. So if you can afford it, you might be able to find it.