It is a strong mix, as I would expect it to need nearer 2 1/2 to 3 Litres, for a 50/50 ratio, but don't know how much your system holds.
It won't affect the running temperature it might eat hoses though, with it being overly strong, but very unlikely, I always run mine around 60%.
There is no way it could cause it to overheat, some countries run 100% antifreeze, where they have seriously cold climates, but it is a slightly different type.
tabetha