Thank you all for your advice. It pretty well confirms what my online searches have revealed. Not sure if I can book T3 on my return when my flight goes from T5, probably not since it is after security, but certainly worth asking. I will wait until my flights have been confirmed before I do anything - they have already been changed once.
Lesley - nice to be in touch again.
Ann - this is a privately arranged trip so no JY deals on this one! I will take your advice re holidays, since this will be in the week after Easter.
Jonah - yes it does include food and drink.
Regards
Sylvia