The question in short: how should we handle a scrum retrospective when the capacity of the team has been very low?
We have a team of 6 people: 1 PO, 4 developers (of whom 1 part-time on Monday and Friday) and 1 developer/SM (me). We have 1-week sprint starting on Monday and ending on Friday 9am, with the retrospective also being on Friday.
Due to varying summer holidays, tomorrow our sprint retrospective would be with one developer who worked Tuesday through Friday, the part-time developer (who did not work this Monday) and myself, having worked the full week.
I'm in favor of not skipping the retrospective, because I find inspection and adapting important. However, I fear we won't get much value from it, because only half the team will be there and only two of them have actually worked in the sprint.
Would it be wise to still hold a retrospective for this sprint? If so, what kind of activities would be useful for this kind of low-capacity retrospective? If not, should we skip it altogether or try to move it to another moment?