@Newbie1925 I can tell you that using no probe, no alarm, etc I have gotten decent results on a Big Green Egg, even when going overnight. Only a handful of times have I woken up to a grill that is too cold. Heating up the grill without overshooting temp is easy with a Kamado. You make sure you light enough charcoal, then close the lid with the bottom and top vents open. The dome temperature gauge reaches your desired temp WELL before the grill is heat soaked. Once the dome temp reaches your desired temp, then you close your vents down. I've seen it a bunch with KKs, for 225 it's just that quarter turn up top. When burning the grill in I think is a great time (as others have done) to start with vents constricted and slowly open them and register the temperatures so you get to know your vent settings from the getgo.
As far as the longevity of a fire overnight, a lot of it has to do with the way you set your fire and what kind of charcoal you use. Not having too many small pieces of charcoal inhibiting the airflow in the basket, for example. Anyway, like you I'm looking at the meater. I don't mind waking up, either. Now that I'm grilling / smoking on this level it feels like a drop in the bucket and more than ever I will want my food perfect.
As far as the rotisserie, I've read mixed reviews. Some people on this forum say it's unnecessary and it's more equipment to store, etc. But there are some stunning pictures of cooks using the rotisseries. With as much cooking area as we have on the grates of our 42s and with such great refractory insulation, you don't really "need" a rotisserie to get fantastic results. However, I'm sure there are some results that you can't replicate without one - like how crispy you can get the skin on a rotisserie chicken on all sides. I'm sure you can achieve very similar results without one, but like everything there's an "ideal" solution and the rotisserie probably is an "ideal" solution for a couple of things. For me, it's not the ideal solution for most of what I do and I think the things I would use a rotisserie for will still come out VERY good without one. I don't want the extra equipment. The main thing I do is smoke lots of meat (pork butts, ribs, briskets, etc) - (and I grill as well). The 42 seemed like the ideal grill and because it is a KK, an amazing smoker too that I can use for a HUGE crowd.
My guess is I'm going to be getting rid of my old BGE and gasser since this thing is so massive. IDK maybe not - there's a practical use for multiple grills sometimes. Anyway - I'm getting excited. It's almost irrational how excited I am.