It is possible. As long as the protocol allows sending bytes of data controlled by the user which XMPP allows.
You would basically wrap http with XMPP. You need a server that would understand XMPP, read the payload, create the http request, do the request for you, wrap the response with XMPP and send it back to you.
You can do that with DNS as well which would bypass probably everything. However, your bandwidth wouldn’t be great.