I think perspective is important. Dd really was reliable by 7 months, but the thing that really matters is the relationship and the connection. The point is to just gentle them through the process, and normalize the whole thing for them. Some of them are better at it than others. Though, all 4 of mine could certainly hold it. Maybe they were dehydrated, lol. Ds was a pee machine, though. I felt like I had to take him all the time. And, sometimes they get frustrated with the whole thing, too. When they start getting mobile and having more opinions of how to spend their time, sometimes they balk at being taken.
As far as over winter, we've always lived in warm houses, so we just kept up what we were doing. I was never super concerned with catching every one, but rather responding to their needs. So, if she didn't feel a need to be taken, I didn't push it. Most of the time, she would, though. For his first winter, ds always wore a flannel button up shirt, and an aristocrat shortie. Aside from the potty thing, I like their knees and toes bare for crawling. Anyway, mine have always worn a diaper of some sort, and only transitioned when they consistent.
So, basically, my babies wore a diaper, and regular clothes if we were going somewhere. I took them when they cued me, or once or twice an hour (or more when they were really tiny.) On good calm home sorts of days, especially with a newborn, it would go something like this...baby wakes up, nurses, pees, plays, gets a new diaper, nurses, sleeps, repeat (over a 2 hour time-line or so). When they start being awake for longer stretches, I might take them again before they nurse back to sleep (or be put in the wrap to sleep). Even bigger, and even more awake time, I offer/change them once an hour, and also take them if they ask.
I look at it like learning to talk. It's just communication, and it can be relaxed and easy. Sometimes they initiate, sometimes I do, but we're both learning and growing and being a team. Over time, they trust me more, and I respond better, and they tell me more and more often they need to go. If they don't want to, like I said, I don't push it.
Books wise...I read a book by Ingrid? somebody called Diaper Free? I think. Other than that, I just tried it, and developed my own system.