According to a country list drafted by The University of Notre Dame the country that is the least impacted by and/or best equipped to deal with climate change is Norway. Other winners are (in order of appearance): 2. New Zealand, 3. Finland, 4. Sweden, 5. Australia, and 6. Switzerland. Canada scores 13th place and the United States 15th.
The country list is highly correlated with a list of gdp. No surprise. On the one hand the index looks at the extent to which a country is exposed to climate hazards and how sensitive its systems and sectors are (such as water, food, human habitat, energy).
On the other hand the index takes into account how much a country can invest to deal with and adapt to its climate hazards. For example droughts, superstorms, migration, fire and civil conflicts. A country that can invest relatively easily in adaptation has a strong economy, a non-corrupt government, strong education systems and a good (it-)infrastructure.