Is the M81 group bound to the Local group? Andromeda and the Milky Way are set to collide in 4bn years. Will the Local Group collide with M81, and what about further away groups? if so, when?
Interestingly enough, although we tend to group galaxy clusters together into superclusters, superclusters are actually not gravitationally bound. This suggests that, due to Hubble flow, galaxies in separate clusters will never "collide". In fact, it may be impossible to ever leave one's galaxy cluster.

EDIT:

In a previous version of this post, I stated the the Great Attractor may be reason to suspect a gravitational binding of Laniakea. In reality, the Great Attractor only reduces the expected relative velocities of these galaxies away from one another by between $200-400$ $\mathrm{km}\cdot\mathrm{s}^{-1}$—I would like to thank eshaya for pointing out my error here. Due to the current expansion rate of the universe of $67.6^{+0.7}_{-0.6}$ $\mathrm{km}\cdot\mathrm{s}^{-1}\cdot\mathrm{Mpc}^{-1}$, some galaxies in Laniakea have recession velocities of up to $30000$ $\mathrm{km}\cdot\mathrm{s}^{-1}$, as given by Tully et al. (2014)—far greater than could ever hope to be counteracted by the Great Attractor.

The question now becomes one of whether the M81 Group is gravitationally bound to the Local Group. Given the M81 Group's status as being one of the closest to the Local Group, at only $3.6$ $\mathrm{Mpc}$ distant, I would not be entirely surprised if through some chance it managed to be. Given the current estimate for Hubble's constant, due to Hubble flow the M81 Group would be expected to recede at $\sim243.4$ $\mathrm{km}\cdot\mathrm{s}^{-1}$. This is what would need to be countered through gravitational effects for the two groups to be bound, and thus eventually coalesce.