I sold my house in June after I moved here. I didn't have power of attorney with anyone, so if you do I imagine it will be much easier.
The closing attorney Fed Ex'd the papers to me, not realizing is it a 2 day delivery where I live. [Meaning I got things back 2 days later than they wanted me to, simply due to double the in transit time]. I had to get my signature notarized on the deed. I was able to contact a local solicitor who did notary service, they seem to be a specialty and I had to call around before I found one willing to handle an international document. He charged me £25 and faxed it back to the closing attorney in the US for me. The loan closed on the faxed documents, but the proceeds didn't disburse until they got the originals back - by then my loan payoff had changed.
Getting Fed Ex to pick up the package for delivery was a nightmare and it took 2 days and several angry calls from the first time I called them before anyone actually came to pick it up. I used Fed Ex only because that is how the closing attorney wanted it shipped and they had provided an account number. I'd not recommend them if you have a tight schedule timewise.
Figures had changed in between the time I received the papers and the actual closing, so after all the hassle I'd signed papers that were no longer accurate. Looking back I'd have someone be my power of attorney simply due to the unexpected things that always seem to crop up at closing. Part of my frustration was with my Realtor, who claimed to be well versed in foreign closings but apparently had no clue. Your experience may go more smoothly than mine did.