Howdy Ashley,
That is a very interesting question! I can think of a couple of ways to do this:
Give those events an arbitrary date, maybe far into the future or past. For instance, if they were all hosted on Jan 1st 1970 it is unlikely they would show up in peoples usual queries.
Another option would be even better, but require some programming. Like the above you could list all of those events on a date in the past. Then you could add a custom field to your site. Something like “Planned Date”. You could then create a filter. In that filter you detect if the Planned Date field is set. If so, you might override the start date field with data from Planned date, and set the event to be an “all day event” (which hides the end date. The reason you would do it this way instead of creating a simple theme override, is that this should override the data for all list views in addition to the single events view. Please let me know if you want to implement this and need me to elaborate any.
Does that make sense? Will that work for you? Please let me know. Cheers!
– Brook