London 2 Monte Carlo Bike ride - help needed in Nice

I am cycling from London to Monte Carlo 25th July to 4th August with a few mates. Three of us are flying back from Nice on Monday 4th August, we have an issue getting our bike bags ( bikes go in padded bag on plane )to Nice. We are looking for either someone in Nice to post our bags to or someone to pick up 3 bike cardboard packing boxes from a local bike shop so we can pack our bikes on the Monday morning, also a hotel close by would be useful. Any help or recommendations greatly appreciated.

Thanks Tony