I asked Aran a similar question about gofyn + wrth under the Tiny Questions with quick answers thread and he responded:
and Gareth King confirmed this:
I have also asked one of my tutors about how much should be included between the dweud and the wrth, and she said, everything(!), even if it makes it a really long sentence before you find out who was involved in the conversation! I don’t know if the same thing applies to gofyn.
I should think it’s all fairly flexible in conversation, after all the person who was told something might be more important than what was actually said - you might want to get that information out first! Also, in my case, where I am likely to forget the wrth after dweud, I like to get it in early in the sentence!