Possible to have unlimited iCal limit on individual feed?

I’d really like to have an unlimited limit for an individual iCal feed that overrides the iCal limit.

We have hundreds of recurring events in one category and want to only display 2 months of that (as it’s too much load on the server otherwise) and another that could do with having all its events fed out as there are only a few a year.

Is there any way that this can be done?

I’ve tried playing around with the functions in em-ical.php – modifying them and putting them into my theme functions.php together with a different ical.php ie ical2.php in my templates folder in my theme. But nothing really worked out.

https://www.ads-software.com/plugins/events-manager/