Dear Thor,
I visited Thrace 2 years ago. My friend Maykel made a report of the trip:
http://maykelfieldreports.blogspot.nl/2 ... -2014.htmlWe found S. salamandra near Stavroupoli (is that still Thrace?), not near Alexandroupoli (but we focused more on reptiles). I saw one Ottoman viper, somewhere in a field east of Alexandroupoli, and no ammodytes. You will find herp densities to be quite high (especially tortoises but also Malpolon insignitus, Typhlops vermicularis).
Make sure you arrange a permit beforehand when you plan to visit the Evros delta and make sure you're out before dark, then you'll be fine. We encountered no problems (and usually we do run into problems on these trips) but I guess things are a litte bit more tense right now (a lot has changed for the worse in two years...). We hiked up to the Bulgarian border and that was no problem (Bulgarian border guards on the other side of the fence were a bit surprised and wouldn't let us cross though), but again, things may have changed since then. Personally I liked the area around the Nestos river up to the Bulgarian border more than the far east (less desolate, nicer towns, nicer scenery and in our case more herps) but no Ottoman vipers there of course.
All in all it's a great area, even if you don't see herps. I'm sure you'll have a great time.