Each Vizlsa will be different, they're not all the same. Some are very content to be couch potatoes until the bell rings, and some are a high wire act from the get go.
As for the time element. No human can out work a Vizsla. You will never have the ability to tire one out. An hour off lead,twice per day is actually pretty good, but be aware, that an in shape, working, Vizlsa can run for hours. I used to run mine with my mountain bike for hours in the forests.
Be very honest with the breeder about what you are looking for. Don't pick a big name kennel known for horizon hunters, or get the Vizsla puppy with the Dual and Triple champions on every side of the paper, with multiple NAVDHA prize titles, unless that is what you know you truly want.
Let the breeder help you pick the puppy that is right for you.
You'll never beat a lesson into a dog, you just beat desire out.