Yes, most restaurants, shops and hotels accept Visa and Eurocard and some of them also American express, but not all.
Is it safe to drink tap water?
Yes, it is safe, we all do it here. Bottle water can be bought in al supermarkets and gas stations if you prefer that.
How should I dress?
In Iceland should always be prepared for changes in the weather, even in the summer. During winter time we have on average temperature around 0C / 33F and in the summer 10C / 50F. Sometimes we have strong winds so wind and water resistant clothes are good. Also good to have hat, gloves and good shoes. Nothing extreme, just ordinary autumn / winter clothes you would use in Europe and N America.
Do you have Uber?
No, but we have taxi that take you anywhere you like.
What is the best time of the year to come to Iceland?
That depends upon your interests. In the summer we have the bright nights and better weather, but in the winter we have the northern lights and colder, even though the climate is milder than most people think. So it´s difficult for us to say which time of the year is the best.