Whether that is just to quilt by stitching in the ditch, to stitch straight lines or even free motion quilting it. Or hand quilting it (which I believe will take even longer).
In the end, it will depend mostly on two factors.
One, the final outcome.
Whether you want it densely quilted, the overall fluffiness of the quilt, the look you are targetting for etc.
Two, the time it will take to complete the quilting.
Time will vary for different people depending on their capabilities. However, I do believe that with enough practice and motivation, one can master all type of design motif easily.
Though, they’ll still have to think about the time for some quilting designs are denser and requires a longer time to get it done.