I am currently at 5 months (22 weeks) and the most I've left Stanley alone (crated) during the day is 3.5 hours. He was fine, needed a fairly urgent wee, but no adverse effects. I would go up to 4 hours if needed, but wouldn't make a habit of it in the crate. I am currently planning to introduce an indoor pen so that he doesn't have to be confined to his crate, but I don't yet trust him not to wee on the floor. He is house trained, rings a bell to go outside and rarely has accidents, but I'm not sure that would be the case in a pen. Time will tell.
The early days were very tough. We got him at 9 weeks and I took 2 weeks off work foolishly thinking I'd have things sorted by the time I went back to work. I did not. Crate training takes time, toilet training takes time, everything takes time, and it's very stressful if you're also trying to juggle work. You might be up in the night letting him out for a wee for the first 4 weeks, or maybe you'll get lucky. I had the benefit of being able to work from home (still am) and it's still been incredibly tough.
Everything got easier at about 4 months when he stopped biting everyone, got his toilet training sorted, and was much easier to be around. Prior to that I have to admit I didn't like him very much and regularly questioned my decision to get him!
Much of the advice you get here will "depend on what you get" - Not all cockers are the same, some are chill, others are nutters. My Stanley is somewhere inbetween