Going to a wedding in Norwegian mountains in July, what do I wear?

[jujubean]

Help! I had great plans to go to John Lewis and do the personal shopper thing because I can't be bothered to trawl the shops, however they aren't taking bookings for the one and only Saturday I can get there without children before the wedding. So where do I turn but mumsnet - please do some personal shopping for me.
Wedding is in Norwegian mountains in July so I'm thinking I'll need a jacket/dress combo to cater for a hot or cold day. I don't think a trusty pashmina around the shoulders will keep me warm if weather is cold.
I'm 5'2", size 10 but with big boobs due to BFing, so prob a size 14 in boobage area. I suit more tailored stuff than floaty, drapey stuff.
Thanks.

[hairymelons]

What's your budget? If you don't mind soending a bit, try Reiss. Beautifully tailored outfits. I don't own any myself (too poor) but my sister and friend have loads of gorgeous stuff from there.