Hi Philipp,
For remote work where everyone is in a different location, the key constraints for the facilitator are keeping the conversation going without visual observation of the group, and engaging everyone in the discussion.
The preparation is almost the same as for a large workshop, so the facilitator needs to choose a set of topics upfront, and perhaps come up with some initial examples that would reflect the scope.
I suggest using audio-conferencing with screen share, ideally some collaborative way of note-taking. We tend to use mind maps when discussing topics, other people use excel/google sheets or some type of online whiteboard. collaborative editing will be better than passive screen share as more people can join in, but it's not critical.
For the discussions, I suggest running a quick introduction with basic examples, then letting people suggest additional ideas until a clear structure emerges for the discussion (That's one of the reasons why I don't like starting with excel, it constrains the structure too quickly). Instead of the usual way of discussing examples with a physically present group, I suggest doing boundary analysis so that people only propose boundaries by listing inputs, and do not provide their opinion about the outputs/outcomes yet. Then the facilitator should choose some examples from the group to run feedback exercises to point out differences in understanding and further topics for discussion.
If you participated in one of my workshops, feedback exercises were those parts where everyone wrote their opinion on a sticky note individually, then we compared the results and looked for differences. Remotely, you can ask people to write down the outcome on a piece of paper and keep quiet about it. to speed things up, you can do so even for a whole group of examples instead of doing them one by one. As a facilitator, you can then ask someone to say their answer out loud, and ask other people to complain if their answer is different. Then discuss the differences, and either get the decision makers to provide an answer, or note the example as an open question for follow-up discussions if nobody in the group can provide a definite conclusion.