Question

Is intergalactic travel possible or improbable? Why so?

Answer 1

Improbable.

Explanation:

Intergalactic space (IGS) is near-absolute vacuum but not vacuum. The very hot hydrogen plasma in the void (one highly compressed and confined atom in a cubic meter) is highly conductive to produce nuclear fusion. This density increases with distance from the galaxy. Reference for IGS:
www.universe today/empty 30280/intergalactic-space
.