We have a 54L (or quart, I'm not sure but it's big) igloo coolbox which is fantastic. The fastening clasp did break though a couple of years ago and I used a bungee rope to hold the lid down but I just discovered that I could buy the part I needed so I have now replaced that.
I usually cool it the night before a trip using frozen milk cartons so that I'm starting with a very cold inside. Recently we were away for 5 days and swapped over cool blocks once only whilst we were away. Everything inside stayed super chilled.
I think it costs about £65.