I've had a look at Vila Nova de Poiares on google maps. It is only a couple of kms from Vila Cha.
Both look big enough to have a PT/SAPO adsl-equipped sub-exchange.
Provided you property is within 4,5 km to 5 km (by phone line - not as the fly crows) of one of these sub-exchanges SAPO ADSL should be possible. However, a big caveat. It may depended on the quality of the infrastructure and cables.
The likely applicable tariff will be this:
This property for sale here:
has adsl according to the post.
It is about 5km from Vila Nova de Poiares past Vila Cha.
I suspect the area is fairly well equipped with adsl equipped exchanges..it will just depend how far you property is from one.
I also suspect that you will be tied to using SAPO as most other ISP's do not find it commercially viable to offer adsl over landlines outside urban areas.