Let's say the Earth got knocked a bit silly in the distant past and somehow space-loving life evolved on this planet. They roll around on an Earth with an axial tilt of 98°. How much harder is it for this species to go visit the moon (which was unaffected). What about rest of the planets?
For a Moon mission, the difference is very small.
Even if one makes no attempt at picking launch sites other than the equator, or don't use any inclined orbit, the resulting lunar transfer orbit isn't all that bad:
A apogee velocity of 190 m/s tangential to lunar orbit, instead of parallel to lunar orbit increases lunar orbital injection (and escape) cost by 70 m/s. That's the easiest burn of the whole mission getting 10% more expensive.
For comparison, this is about the same delta-v advantage one gives up launching from Cape Canaveral instead of the equator, which means that our hypothetical Uranus-Earth moon mission has pretty much the exact same delta-v budget by launching from the equator.
For an interplanetary mission, there is no difference.
When entering a planet from solar orbit, one can pick any target orbital inclination by picking which side of the planet one enters from before making the breaking burn.
Since orbits are time reversible, this also means one can launch a spacecraft into the ecliptic plane from any LEO inclination at equal cost. Interplanetary spacecraft already do this all the time, and this would be no different on Uranus-Earth.