I think they would do it off season; the lady herself would certainly do it but I don't know how you get to her if you're not there.

We stayed just outside of Chania several years ago and loved it. Chania is a lovely city.

I thought Sitia was great as a base in eastern Crete in terms of visiting nearby archaeological sites (Zakros, Palaikastro, etc). The archaeological museum in Sitia itself is a plus. I found Sitia a bit calmer than Aghios Nikolaos (which btw also has a nice archaeological museum).
Matala in the south is another good base if you'll be looking at archaeological sites down there (Phaistos, Hagia Triada, etc).