I recently picked up a silca elettrico ultimate and I’m quite smitten with it. I’d love recommendations for a saddle bag that will fit it securely and dryly, but doesn’t need to carry anything else. The remainder of my flat kit goes in a bike wallet in a jersey pocket.
Another vote for Ortlieb. A plus is that the adapter is available separately so you can use the same bag on multiple bikes and/or have different size bags when you need more or less stuff. (My Brompton Ortlieb is bright green to make it stand out from the others, which are basically interchangeable in terms of their default contents.)