Yea, 3-4 occasions requiring dressy dress seems really excessive for one wedding. Yea, a wedding weekend is nice and all but there's no reason why anything more than the actual wedding should be formal. The evening before sounds a bit like a rehearsal dinner in the US and while I wouldn't wear jeans and a T shirt to most rehearsal dinners, I'd imagine that most people would already have an appropriate outfit in their closet already (ie, a cute sundress or skirt or slacks with a cute top). Day-after brunches are also common and great but decidedly casual, in my view, where jeans and a nice top would be totally fine. This sounds way over the top!