There are hub adapters, BUT they are expensive, and the wheels will need to be a very high offset, because the hub adapter needs about 20mm of room.

Filling and re-drilling, would NOT be reccomended.

Post a pic of the wheel, maybe we can find a similar wheel that will actually fit.

The safer way to do it is to remove the hubs and have them, along with the rotors, re-drilled to fit the wheels. This is a PIA, but not particularly unsafe. Redrilled wheels OTOH I would never trust. When redrilling hubs, don't weld up the old holes and re-drill them. Rather, offset the new pattern in relation to the old pattern, so that you have 10 holes in the hub now instead of 5.

Re-drilling hubs is common on oddball cars. A lot of Fiats (4x98) Yugos (also 4x98) and early Civics (4x120) have been redrilled for 4x100. As long as the hub is redrilled I'm OK with it.

5x114.3 is so common though, that it's hard to believe that there is a wheel that can't be had in it. If the wheels you want are aftermarket, then you can probably pay a custom charge and have the wheels drilled the proper pattern at the factory.