Commuting distance recommendations

Hey everyone!

I'm thinking about making the jump to eBike commuting full-time and wanted to tap into your collective wisdom. My current commute is about 12 miles each way, with a few decent hills thrown in for good measure. For those of you who commute regularly on your eBikes, what do you consider a comfortable or "ideal" daily round-trip distance? Are there any distances where you start to feel the battery range or comfort becoming an issue, even with a good eMTB or commuter model?