Is it possible to setRouteVariables when redirecting after a successful form submission?
Other than the query string, you're options are:


Save it to a cookie and retrieve it from the next page with something like this plugin.
Save it to cache (craft()->cache).
Save it to PHP's $_SESSION, which Craft wraps with HttpSessionService (craft()->httpSession).
Writing a plugin with a Twig function that wraps Craft's craft()-&gt;userSession-&gt;setFlash() method, which will store a key->value pair in session for exactly one request. You can retrieve the value via craft.userSession.getFlash().


Note that there are limitations to the size and complexity of the data you can pass along with all of these and in almost all cases, the data needs to be serializable.