I know this topic comes up often enough. I came across this special suitcase that is designed to carry back several bottles of wine, with built in protection: fly with wine I don't expect to ever need one, but I thought it was interesting enough to point out. If you dont want to look, its a hardcase suitcase with padded holders to keep wine bottles (or whatever) apart from each other. And they can be removed to allow for only as many as you want, and then the rest of the space is usable for regular packing. There are probably other brands as well.
We own the 12 bottle suitcase and it works great! Has always weighed under 50 lbs as checked baggage when full of wine. We have taken it across the pond a couple of times when we are renting a car. The downside is dealing with a large (and heavy when loaded) third suitcase on trains or other public transportation. You also have to pay to check a second bag each way if you don’t have extra baggage allowance. We use it mainly for trips to domestic wine destinations where we pick up bottles at various wineries and it makes it easy to get it home. When we toured the burgundy region of France - there was a program where you bought wines at different wineries and the service picked them up/packed/shipped them to us back in the states. It is not a cheap suitcase but well built. It has paid for itself in wine shipping costs.