FWIW…and I don’t know if I’d include myself in the big volume bunch…
My year-round average is ~11-12 hours per week. Over the last 5 years, I’ve done 7 IM’s (with #8 in April, and 9 in June) so that has helped to keep my schedule fairly constant, and fairly consistent so far as periods of total recovery (at least 4-8 weeks per year of zero/<5hours of volume) and big builds are concerned. Looking at my ‘official’ IM prep period of 12 weeks before the race, the weekly average jumps to 18 hours per week. That number gets further skewed by periods of 3-5 weeks where I’ll really ramp up the volume (four of the last five weeks, for example, were between 23 and 27 hours). The easy way to say it is that I’ve been in a constant cycle of ramping up to big volume, then tapering down to a race, then going into total recovery, and then starting the process over again. And, when I start the process over again, I start with very small volume. I would also note, that by a long-shot my training for the next IM is the most I’ve done over that span of big weeks.
next weeks? I’ve found that doing one big week/end of training doesn’t really do much for me. So, I like to stack them up in 2-3 week cycles. However, I’ll try and alternate the big volume between bike and run so that I’m not doing huge weeks in both at the same time. Although, I have done it - the fatigue and recovery is too great, considering I have a normal life I have to juggle as well.
times? I don’t have any recent HIM times as I only did World’s Toughest in my 2nd year of tri, and I hadn’t yet gotten into bigger volume training. As far as IM, I’m still not ‘fast’ like a lot of others on this board, but I have taken my time down from an 11:57 to 10:27. I am shooting for sub 10 at IMAZ next month. People come into this sport from different starting points, so different levels of effort are required to get to certain performance targets…at least, that is what I tell myself 
SO is very supportive as we both make sacrifices to accomodate my tri training, and her running. I tend to workout very early and at lunch time, or when kids have activities in the evening that don’t require my involvement/being there. Of course, it’s never fully balanced.
Nope. I actually find that the more training I fit into the day - the more organized I am at work. Plus, you adjust to the sleep schedule required to make it work.
Finally - doing big volume training doesn’t always have to be for the express purpose of getting faster - sometimes, it can be for the simple reason of enjoying biking and running long distances day after day.