The Millers hit rock-bottom County with four goals in a 17-minute blast in the first half - James Tavernier, Haris Vuckic, Alex Revell and a Kieran Agard penalty doing the damage.
Vuckic grabbed his second of the afternoon on the hour mark before the home side added a sixth through Tom Hitchcock.
Evans said: "We just seemed a bit tired after the game at Preston (in midweek).
"I think from the second goal it could have been any score. We showed our class, our effort and our fighting spirit and willingness to work for each other.
"It's very easy to come in and be disrespectful of the opposition when you've won by such a good margin, but Notts County have got good attacking players and they have shown that on many occasions this season, but we said the first goal was all-important.
"We got that and we stepped on from there on in and it was as good an afternoon as we could have had.
"We could have had double figures. There was super play and super chances and the 'keeper made two or three fantastic saves.
"I think we've shown here we have got a squad of players to get us in this play-off group. We are fighting desperately hard to be in the play-offs."
Source PA