Hi, Dan. Thanks for getting in touch about your question.
The WooCommerce Tickets add-on provides integration between The Events Calendar and WooCommerce. That said, if the WooCommerce engine supports the upsell that you’re looking for, it’s likely that it will work.
Without a little more detail, I’m afraid that I can’t give you a definite answer. Also, it may be that this is something that the folks over at WooThemes might be better positioned to help you out with.
Please let us know if we can answer any other questions for you.