Ah thanks it makes sense nowFew videos at a time for a few reasons. One it means you don't get sick of the game too quickly plus if you try to do iT all you have to try and stay in your 'personality' for hours at a time and that is incredibly difficult to do so by the end you usually have really poor videos because you're bored and can't keep the 'personality' going. Also if there's certain things you don't understand about the games or mechanics coming back fresh can help you realise what you should or need to be doing and if your audience gives you tips you can actually implement those tips rather than ignore them because the series is already complete. One last point is if the series really doesn't do well or you aren't happy with it then it sucks if you have spent all that time on it and it's not worth releasing.
Thanks hope to record this week and upload by the weekendRecord sessions of about an hour, then you can split it up into 3-5 videos (depending if you want videos around 20 mins or 10-12 mins), upload the videos regularly and keep recording more of the series when you run low, like a top up! For example, I currently have 3 videos rendered of a game I'm playing, when I've almost ran out of videos to upload, I'll go to record more, render them out and repeat.
Try not to wait too long between recording the same game though, if you forget what's going on it ruins the viewing experience a little, especially if the viewer is watching every episode back to back and half way through you're like 'wait whats happening here'.
Hope that helps, good luck!