Diode N value less than 1 for temperature sweep
Regarding LTspice, you cannot simultaneously use a .TEMP and a .STEP command .  

.TEMP is an archaic form of the step command for temperature. It is equivalent to  

.STEP TEMP LIST &lt;T1&gt; &lt;T2&gt; ...


which reveals why adding another .STEP command yields no simulation.

Just use e.g. a transient analysis, like

.tran 1m
.step temp list 0 20 40 60 80 100
OR
.temp 0 20 40 60 80 100


to step the temperature.