Boden retro pocket dress - cardi help?

[lebasi]

I have just bought this dress www.boden.co.uk/en-GB/Clearance/Womens-Petite-range/WH469/Womens-Retro-Pocket-Dress.html# in the sale. I am in two minds about it - to make it work in the English weather, I will need a cardi to go with it, and don't want to keep it unless I am likely to be able to get a cardi (I don't have anything that works). Any fashionistas able to help? I only have 7 days to send it back if I can't find something! Thanks in advance.

[MoonlightandRoses]

Rather than putting a cardi over it, would you be able to fit a fine knit jumper under it?

Gap generally have some lightweight wool ones in, in various colours

selection of cardis & jumpers from Gap