So I think, your options are to 1. Get a second script from that reservation service that uses a different iframe unique id for the second reservation form, or just use one of those forms per page in Webflow.
One more thing, you should consider, is that the scroll interaction you have set on the reservation window, will not work on iOS devices (should work on android etc). Currently scroll interactions are disabled on iOS touch devices mainly because the way they refresh content (based on touch events, not scroll events), so any element which has a starting interaction to display the element with opacity set to 0, would be shown visible at start on iOS devices.
So you might rethink this particular scroll interaction, unless having this window open at start on iOS devices is ok with you.