I think that nearly two hours exercise a day is more than enough, even for a working cocker. And I reckon if you have had a typical terrier, you will probably be ok with the temperament of a working cocker too (both can be a bit mad at times).
I have a cocker which is half show, half working. I never planned to have her, she was an emergency foster that stayed. She struggled a lot with self control when she was younger and I had to put a lot of work in. And if I had let her, she would have demanded hours and hours of exercise too. However, my dogs get one to 1.5 hours a day (that's one walk a day) and she is perfectly fine with that now and is very settled and relaxed at home.
The one thing you have to remember which working type breeds is that they usually need more mental stimulation than show types. In other words, you will have to come up with some training opportunities, be that pet classes or once she is older, agility, fly ball etc. Yes, working types need a decent amount of exercise re walks, but they need just as importantly the mental exercise! You keep that in mind, I am sure you will be ok.