Here are few other ways I see we could do this and possibly help us in a much better way:
(1) Instead of populating the activities for every time for selected category or dates - it would be good to ask the viewer to select the options that they are interested in and then click on "display results" to see all the activities. Also, to be redundant but be helpful to our users, we could have preselected categories for them to select and with one click they can see upcoming trips, activities and events for the respective category, similar to that we have on our member activity pages to display trips, course activities and events. I see these categories to be Hiking, Sailing, Canyoning, Basic Climbing, Intermediate Climbing, Backpacking, and other "I want to go" categories.
(2) Create a page that course leaders and committee chairs can share where the upcoming activities can be displayed in a better format, such as table where filtering and sorting is possible for the viewer (similar to the table seen in "view content" for course materials and such) to play around easily and find the trip or activity of their choosing. This page can be customized for each committee and sub-committees.
(3) Simplify "I want to go.." categories to already include difficulty level included such as Basic climbing, Intermediate climbing. "I would like it to be" categories can be removed altogether - which encourages the user to ready more leader notes and descriptions than to rely on such terms which at times do not accurately represent the trip/activity. "Trip, seminar or clinic", "For adults, families or youth", "With this branch: Seattle,..." to filter from the already populated results and not spin the wheel to display for the new search results.

Hope I am clear (which I doubt), so happy to discuss my ideas with you more on a phone call or answer your questions as needed. Thanks for your help and looking at this website feature to be possibly added for our use. Much appreciated!

Thanks Jeff for your comment.. I don't see it on the thread for some reason so I'm reposting it here:

"Try using our site search, the box in the header with the magnifying glass. You don't have to enter any text to start the search--just click on the magnifying glass and filter from there. Here's an example of a site search for activities next weekend, Sep 3-4."

This works well for my use case. I'd be curious if we have data on how many searches are done that way vice the "Find Activities.." and "Find Instructor Opportunities..." paths. My pure guess would be that most folks use the find activities link.

When I think of my trips, when I post them, they usually fill up because people get alerts. My experience (and maybe I'm just projecting here, haha) is that is that people don't necessarily jump on instructing opportunities at the first opportunity. So there's two kind of users: one that signs up for things of interest the hear about via alerts and another that will look to see what's available the upcoming weekend that sounds interesting. I think its that second crowd that this idea would be useful for.

I think this is a great idea that would simplify finding volunteer opportunities as a whole for the organization and courses. I have heard from a number of members that it's difficult to find what is available for instructors/volunteers, and having to go through a number of web or course listings/ pages to find this information.

Several of our courses keep on struggling to find enough instructors year after year. Anything that will lower the threshold for instructors to find opportunities for teaching can make a huge difference.
Jan, Basic climbing chair

I frequently use the "Find Activities" with a date filter to see what's going on on a given weekend before I post something. Occasionally I think a place is free only to find when I try to post it that there is a course activity there. Manisha's suggestion would make it easier to answer the question I really have which is "what all is going on this weekend?"

I see that we can also get to instructor opportunities via courses->find instructor opportunities but my feedback idea still stands - as a volunteer led organization, it'll be very useful for us to make finding instructor/volunteer opportunities be part of all activity searches.