Thanks everyone, in the end she stayed with me until 1.30pm, and my husband took her back to MIL place, she wasn't due for a feed until 4ish as i fed her just before she left. I expressed just before we left for the wedding, she drank her bottles perfectly and there ended up only being about 60mls left of what i expressed for her. (i ended up sendng 500ml) i rang between wedding and reception and she had fed beautifully from bottle and was sound asleep so i went and expressed at 7pm ( i had my pump with me just in case) we got home at 12pm from wedding she was sound asleep and had fed at at 11ish so i expressed a bit more and she woke up at 2.30 for a feed.
I had sent the milk in storage bottles and MIL just warmed small amounts at a time to minimise wastage.Thanks for everyone's advice and replies. Much appreciated