Good evening Laurence and welcome to the Events Calendar Support forum!
Thank you for reaching out to us.
I would love to help you with this topic.
I totally get where you are coming from. It is really nice to have a one-stop solution.
Unfortunately, at the present time, the email features we provide are fairly limited for attendees.
But we are absolutely working on improving that. So stay tuned!
In fact, there is already a conversation on a similar feature in our User voice forum: https://tribe.uservoice.com/forums/195723-feature-ideas/suggestions/8391186-reminder-emails-for-x-days-before-event
In the meantime, the only workarounds available are the ones you mentionned:
- Switching over to WooCommerce for RSVP (using free WooCommerce products).
This would enable you to add https://woocommerce.com/products/follow-up-emails/
I realize you do not want to use extra plugins, but that is the most elegant and efficient solution.
- Using CSV exports or automated feeds to populate something like a Mailchimp List.
I wish I had a better answer for you, but for now it’s the best one I have unfortunately.
Best regards,
Geoff B.