Im going to call BS on that theory. Look at SEN. Three based A319s. On many occasions they don't make it in, and they are based there.
If a based aircraft on the last sector of the day does give it a go, then as the night draws on and it cools, the fog will thicken and vis will worsen. I do not believe for one minute having a based plane will impact performance.
Conversely, if a based plane was to operate a rotation from base with a good chance of not getting back then surely the ops department would be likely to cancel both the outbound and return flights so as not to get stuck down route overnight and affect the next days program.