You can import a collection into any Mailchimp campaign using Feedblock RSS Merge Tags. Here is a quick example to get you started, you can use any collection's url, just add .rss to the end:
*|FEEDBLOCK:https://calendar.publisher.com/lists/268.rss[$content=full, $constrain_rss_img=Y]|*
<h1>*|FEED:TITLE|*</h1>
<div>
*|FEEDITEMS:[$constrain_rss_img=Y]|*
<h3>*|FEEDITEM:TITLE|*</h3>
<div>*|FEEDITEM:CONTENT_FULL|*</div>
<div><a href="*|FEEDITEM:URL|*" target="_blank">Read More</a></div>
<hr />
*|END:FEEDITEMS|*
</div>
*|END:FEEDBLOCK|*
You can modify the HTML to add classes or customize the look.
