Thanks all!!
I do plan to do an overhaul of our luggage soon. We have inherited bags from my MIL - and have never really updated them. We have good weekend bags. Possibly I should have accepted that walking from train station to ferry, or bus terminal to hotel etc is a challenge with six people. We did a mix of things from two taxis, to one taxi with 2-3 people plus all the bags (the rest walking), to metro etc. I like the adventure of different forms of transport (we did rental car, intercity coach, city bus, metro, regional train, high speed train, ferry, vaporetto to lots of walking). But 49 year old backs are not as good as 23 year old backs!!
