Let's say the rogue system is 4-40-400 light years away (nearest star is 4 ly).
What's a reasonable ∆v? We get some free ∆v from Earth's orbital velocity of 107,000 km/h, or 29.7 km/s. Our fastest spaceship (which is around sun, https://wikipedia.org/wiki/List_of_vehicle_speed_records#Spa...) is 252,792 km/h, or 70.22 km/s - which isn't including the ∆v to cancel that, ∆v to return to Earth, cancel again.
This 70.22 km/s is about 2 ten thousandths of the speed of light (70.22/299,792). It would take about 20,000 years for alpha centuri (4 ly) to arrive at that speed, and 200,000 years to travel 40 ly, 2,000,000 years for 400 ly.
Of course, maybe we can go faster in future. but propellant is a problem, you have to come back, and a manned mission is orders of magnitude heavier.
Space is big.
funexercise: propose a means of propulsion that could do this.
