Interesting that it happens with only 100 rows. I have a user with at least 1000 in a calendar style layout and I’m not aware of an issue like that.
What if you build your own custom calendar list with one of the other list styles, in combination with grouping…then set the ‘Show only a few Item’ option to something a little more manageable. I can’t imagine somebody scrolling through 6000+ list items. They would probably just use the search anyway.