Too late - I grew up going to stay with my grandparents at Pag a lot during 90s (during the war and after) - I remember the streets were so empty we would play football. Forward to early 2000s and I remember car jams 4km long for some random low-key event in a fishing village (ribarske večeri). These days it's not worth going to any tourist areas during season anymore, everything is overcrowded and the infrastructure isn't built to support that much people (roads, parking, water supply/sewage treatment, restaurants).

Late spring and early autumn are still gorgeous.

If you rent a boat it can be a bit better, but even then it's a hassle with marinas, etc. Just avoid the peak months IMO.