I am also always remote for my company's clients, they are in the US and I am in Greece so that's not an issue.
What is an issue is the bolded bits: I find I start work later too, am less productive per hour, and as a consequence work longer hours, meaning I'm more away from my wife and kids, even though they are one or two doors away. I find WFH lacks the discipline of working from the office, both in the going to work as well as going back home, and a massive time sink as well. Overall my, and my coworkers' efficiency is in the toilet. We deliver the work but we do it in 2-3 more hours per day, at no extra pay, and with the cost of nerves, tiredness and lost family time.
The "little bits of time saved throughout the week really add up", are you sure? I am not having a go at you, but because I am in exactly the same situation I consider these extra time sinks and breaks of focus. Or if for example my wife or kids come to tell me something - if I haven't locked my door, which I now often do even if not on a business call - that can be up to 10-20 minutes or lost time. I am at fault, for sure, for not being disciplined enough. The work DOES get done in the end, but at a higher cost to me I find.
Frankly I think working from home will become the norm for a load of office jobs, I already hear from friend whose jobs (office job) are not renewing their leases and rents and moving everything to be remote working (no extra money dolled to employees though from rent savings etc!) but I'm firmly not a fan.