How to thank a group of co-workers for their hospitality?

Question

The company I work for has an office in Japan, and they've hosted me for a couple of weeks. When that time comes to an end I'd like to thank them for hosting me and making me feel welcomed. What would be an appropriate way to do this?

お-疲れ-様 is one answer I've seen, but it I'm not sure: it seems to be used for small things and I don't want to offend by giving the impression that I thought their work was minor.

edit: I saw that other question about thanking for hospitality but asked anyway to ensure I found something appropriate for a business context. If that question's answer is appropriate, then this question is a duplicate.

Answer 1

お疲れ様 is not appropriate for this case.
If you're going to thank them by speech, the answers posted by Earthliŋ, the links of which are shown by Earthliŋ in the comments, are appropriate. However, I feel that it alone is not enough as the way of giving an address of thanks for their hospitality for two weeks. But I think that elaborate speech of gratitude similar to that of ordinary Japanese seems difficult for you.
So, I recommend that you leave a gratitude letter in English for them, and you say like "皆{みな}さん、長｛なが｝い間｛あいだ｝大変｛たいへん｝お世話｛せわ｝なりました。どうもありがとうございました。日本語｛にほんご｝がへたなので英語｛えいご｝でお礼｛れい｝の手紙｛てがみ｝を書｛か｝きました。あとで読｛よ｝んでください。Thank you very much for your long-term support/hospitality. Because I am poor in Japanese, I wrote a letter of thanks in English. Please read it later." at the speech.

By the way, I think it is quite all right that you would read the draft in Japanese at the speech.