I visited the lakes during summmer, and even I arrived at the opening hour, it was full of tourists. I suggest going there out of tourist season. It is a fascinating national park, highly recommended. There are several gates, and between them you can hop on small buses (electrical if I remember correctly).
I had my wrap with me as there was no vegan options to eat, not even plantbased milk for my coffee.
AlmaCseresznye 