Yes. You will need to either catch a bus or fly internally from Athens to Thessaloniki. Bookings can be made by your travel agent or on your own. Please note that while buses are a little cheaper, you should factor in the costs of a taxi to the bus depot, the length of time it will take you, and the complexity of re-connecting with the team in Thessaloniki. Those who have done this before would recommend flying if you can. You should try to depart Athens on the morning of the 5th of July, arriving mid-afternoon.
Not including flights, the cost per person might be around $1250 (AUD). This figure is based on last year and hasn’t been finalised as yet. Exchange rates could also vary these costs. Note these prices are based on a twin share; if you’re in a triple share or family room, it will be cheaper.
We travel together around an hour south of Thessaloniki by car to the Evdion Hotel (or its partner hotel next door) for a time of de-brief (http://evdion.gr/gr/main). Note, this hotel hasn’t been confirmed yet.
There really is no cut off date as such, but as you can imagine there is a bit of organizing that needs to happen such as arranging your passport, booking a flight, and (for our part) organizing accommodation and transport at the other end. Please don’t hesitate to talk to someone if you think God may be prompting you to go.