Temp?
Filter then winterize?!?
Remember we need excruciating detail here…
Per Sid’s recommendation, see: Iso vs ethonal for why it matters
Personally I’d throw the e.toe pro in the trash and get a rotovap. Mainly because their pronunciation of EtOH offends me 
Edit: get your self a controllable leak: Roto Evaporator issues - #32 by cyclopath
See: I just got a 2L rotovap, will this vacuum pump work with it ? - #26 by cyclopath for boiling point of ethanol at various vac levels (iso should be close).
You’ll notice ethanol boils at -40C if you suck on it hard enough … (which you have obviously been doing)