Isn't a warmer climate better for energy generation?
The real problem, of course, is that it's not going to be limited to a small rise in temperature.  

However, WRT energy generation in particular, most forms of generation become less efficient as temperature increases.  For thermoelectric generation - fossil fuel, nuclear, &amp; geothermal - that's obvious thermodynamics.

Photovoltaic cell efficiency also decreases with increasing temperature (e.g. https://www.sciencedirect.com/science/article/pii/S1876610213000829 ).  The drop in energy production during winter is a product of factors like the shorter day and lower sun angle, not the temperature.

Unless I've missed something, that leaves just hydroelectric &amp; wind generation.  AFAIK, they aren't directly affected by temperature.  Changes in weather patterns might produce more or less precipitation and stronger or weaker winds in any particular location, but I don't think the effects are predictable, or necessarily a net increase.

Finally, increased temperature affects the efficiency of power transmission.  Electrical resistance increases with temperature, so an increase in temperature leads to increased transmission losses, and a decrease in the effective capacity of the lines: https://iopscience.iop.org/article/10.1088/1748-9326/11/11/114008