Heading off down the rabbit hole now
The current commute will be a simple 15 mile-ish thing, parking the bike up in a rack almost immediately outside our area or even bringing it inside. Secure site, no worries about leaving stuff with the bike, and I don't have to look particularly presentable on arrival. I can leave stuff in the office, and there are showers etc.
A pair of Super Cs would give more flexibility than the BB, but not quite as focussed and potentially have a build up of archeological layers of detritus in the bottom.
The Ortlieb commuter insert is tempting, allowing use of the panniers for bulk carrying or organised commuting and laptop storage. I've been a bit down on Ortlieb since I bought a hard box pannier many years ago that failed quite quickly. The replacement similarly failed and I abandoned it and haven't returned to the brand. I'm sure their normal range are much better.
I did used to use the BB for shopping, with the laptop insert removed if I was carrying a lot, so it wasn't just a commuting bag. The extending lid was useful when I bought more than I thought.
Choices, choices.