I would warn group members that you are doing it - "going on holiday!"
Or perhaps not, IMHO. Depending on who can read your group message archive this can be a handy tip - off that your home is going to be unoccupied.
If you do want to shut down all group traffic then this suggests that you do not have another moderator for your group. Unless there are particularly good reasons for this being the case then it is better that there is someone who can step into your shoes just in case there is ever a reason why you cannot manage your group.
