After Upgrade Max Subscribers exceeded, but can’t get to page to sync

After migrating to Mailpoet 3 from 2.8 all of the WordPress subscribers from God knows when showed up (over 8,500). In 2.8 the number shows 0, and the rest of our lists are tiny by comparison. I read the advice to sync the list, but of course you can’t even get to that page because the sad kitty face tells you there are too many subscribers. We don’t have, I’d love to try v. 3, but need way to at least get to the management tools. Could I suggest moving the sad kitty paywall to before someone tries to SEND instead of just getting to look at the migration? Seriously, we’ve been using for years so this is obviously an issue.