In terms how the self-study online courses vs standard in-class experience are viewed by the adcom, the best way to find out is to ask the adcom of your targeted schools.
When I was in the application process, either Smith or McDonough part-time MBA adcom suggested to take the online calculus course from
https://www.graduateschool.edu. I don't remember which school suggested this, but I checked with the other one and they confirmed that a course from graduateschool.edu would be just fine. As far as I remember, you can start at any time and go at your own pace. They will connect you with your online instructor and you work out timeframes with him/her directly.
In the end, it turned out I did not need the class for application and I got admission without it to Smith and GWU, so I just dropped it, as I did not have time for it.
Bottom line, ask the adcom if the online course would be acceptable for them.