The goal should be "errorless" potty training. Or as close to that as you can accomplish. No pity training ones off without a hitch, so don't beat yourself up over the occasional miss, but TRY to avoid them.
There is no clear answer to your above questions because every puppy is different and every puppy comes with a different set of skills. It's like saying "when should my kid be potty trained?" Some precocious children are reliable by 18 months, but EXTREMELY few. Some are not reliable by 5 years. But EXTREMELY few. The vast majority are in between.
I would not allow ANY puppy under 16-20 weeks MORE unsupervised space than this. They just don't need it. And it is asking for accidents. And the more accidents, the longer potty training takes. (and the longer you will need to confine and supervise) And really, you should be spending A LOT of time supervising, playing with and training a puppy in its first 6 months. Between that and their need for sleep, because they ARE babies, the time spent in their expen really should not be onerous.
OK, this makes sense, especially since coincidentally, I did have one human child potty trained at 18 months, and the other at 5+ years. Maybe I'm just struggling because I'm a very scheduled person, but for the first two weeks we've had her, I've been watching cues, and doing things willy nilly as opposed to following a very specific schedule. For example, I've been 'loose' about feeding times, because I'm portioning meals and using them for training (with plenty of rest in between), instead of feeding 3x per day always at the same time and place. I felt ok doing this initially since my breeder had said she would typically have a big breakfast and then free feed the rest of the day (and she didn't have issues with overeating). So I was making sure she got a good breakfast and then train/feeding the rest of the day. Since my feeding schedule is not regular, I don't expect my potty schedule to be either, but as of today, I'm starting regular meals at regular times, and reserving less for less frequent training in between.
To date, I was not watching the clock and putting her on the potty tray at specific times either. With frequent play, eat, train, sleep, I just figure she'll need to go all the time so I just keep watching for cues and going with the flow. When she does start circling and sniffing, she is not seeking out her tray. I always just put her on the tray at that point, otherwise I think she'd go anywhere but the tray. That interrupts her enough that I need to give her more time to actually go on the tray once enclosed in the pen. Sometimes she'll go within 15 mins (then I praise and take her out), sometimes she won't (I take her out anyway after 15 mins and watch like a hawk, and keep trying to get her back on the tray whenever she sniffs and circles again). But not seeking out her tray - is this the developmentally ready part, and she'll start doing this in time when she's ready? Or is it because I haven't been good about doing this at specific times and therefore there is no routine for her to know what's expected? Or both? Is it a bad idea to try switching to pellets at this point, to see if that smell attracts her more than my scented pee pads?
As for mornings - I don't feel confident about how to establish potty routine at that time either, because with access to her tray all night, she just goes when she needs to. So I greet her and try to look for a 'recent' potty when I first come down, to see if she's gone already, but I can't really tell how long it's been if I haven't seen her go. So do I go through the potty routine motions anyway? If so, how do I do that? Do I pick her up to say hi, and then put her back down and ask for potty and walk away so she can do her thing? Do I leave her until I see her go and THEN take her out to say hi? Do I pick her up and take her to a different location and try there (i.e. kitchen potty vs. living room sleeping pen), so that there's some kind of distinction/clarity about what's expected, and to give her a break from the pen after having been in it all night? If I were outdoor training, I'd obviously just take her out and that would become the routine. But since we're indoor training, and the tray is right there in her sleeping pen all the time (with crate door open), I don't feel like I'm establishing any routine, so appreciate your input on how to make sure i'm creating and sticking to routine w/indoor potty.
Also, in the early morning - she seems to always poop around 5am and then starts crying (or maybe she's crying first because she doesn't' want to poop in the same place as her potty tray, and then finally giving up and going on it anyway?). Initially, I ignored her thinking she wanted attention, and I didn't come down to clean up the poop until I woke up at 6:30 (she did quiet down again after the 5am poop when I was doing this). But then I started going down at 5am when I heard her crying, thinking that she's not doing it for attention, but is maybe just stressed about not wanting to get dirty, step in it, and take that back into her crate with her (and I'd prefer not to clean up stepped in poop either). So I've been cleaning it up and then going back to bed for a little longer. What do you recommend in this situation? I don't want to ignore her cries if she's stressed, but I don't want to start bad habits either.