Would humans survive a dinosaur extinction level impact?

Chicxulub meteorite landed on the ocean, an area the size of the USA would become a no-mans zone as fire would rain from the falling debris shot up from the impact. A tsunami would sweep the world several times, its size and destruction would be hard for us to quantify or imagine. 

Then impact would kick dust up, the tectonic shock of the impact would cause massive earthquakes and a global volcanic eruptions, all this would make the atmosphere toxic. 

Then the bad part begins. Volcanic eruptions and impact debris would spread globally causing a 18 month-10 year long ''nuclear winter'', which means for that time the world would be in an endless night thanks to the atmospheric debris blocking out the sun, global temperatures would plummet and photosynthesis would cease. All plant life and phytoplankton would collapse, animal life would follow. The only warm blooded animals to survive would be tiny generalist [small rats, small pigeons]. 

Today there are 7.8 billion humans, we are big warm blooded animals that need a lot of food, with global agriculture collapsing and then vegetation collapsing could we survive?