I got Emmie at 11 weeks old and she is almost 5 years old now. Some folks might say I shouldn't have gotten a puppy because of my (occasional) crazy schedule but I've worked very hard to make it work, including finding reliable people to help out in a pinch. Selecting a puppy with a compatible temperament for your lifestyle is key, which is why finding the right breeder is so important. I think with proper attention and training you can be successful but your life will be taken over for the first 2 years.
1. I work full time outside of the house (with a demanding job) but I can usually work from home 1-2 times a week so that helps.
2. When I first brought my puppy home I was at home for 3 weeks, then she came into the office with me for 3 weeks, then stayed with a trainer friend for 3 weeks (during the day), and then went to a great doggie daycare until she was 3 years old. Now a dog walker picks her up at my condo and takes her out for 3-5 hours a day.
3. I always take Enmie for walks before and after work, rain or shine, year-round. Providing your dog with daily exercise is critical to their well being.
4. A new puppy needs to potty/poop frequently so you must have a good system in place to set them up for success. I recommend an expen, indoor potty, limited freedom, and taking them outside a lot. It was very important that Emmie not develop bad habits so she could go to other people's homes and be accident-free there.
5. I'm lucky that Emmie doesn't require daily grooming like many adult Havs in a long coat. Again, work with a reputable breeder to learn how to best care for your Hav's coat. As she was transitioning from puppy hair to adult hair she matted a lot and I had to have her shaved down but since then she's been fine because I learned how to care for her from the experts on this forum.
6. I spent a lot of time with training classes and puppy/dog play dates to ensure that Emmie was and still is well socialized and has good manners. I can take her anywhere and she is always welcome at my family and friends' houses.
7. Indoor exercise can include training classes, fetch, puzzle games, play dates, learning new tricks, and even a treadmill (with proper supervision).
I commend you for your research and planning prior to bringing a puppy home. It's a lot of work but worth it in the end. Good luck!