hi

The mixture will certainly start of with a lower viscosity if it's warmer but it will also set faster as well (a rule of thumb from chemistry is a reaction will go twice as fast for every 10 deg C warmer)

I havent read the manuals on these yet, but

i suspect that this would be an exothermic reaction, ( , or endothermic ). If so, it might not react properly outside the recommended temp, and the suggested temp, may be the temp that it hardens the best at.
The rule of thumb mentioned above in the quote, would generally only apply to a stable compound, not a 2 part mix, especialy if that mix is exo or endo thermic