Mini Z’s, IWavers and XMODS are all the same scale. Neither of the 3 will cope with roads unless its bitumen like at templestowe race track.
The mini Z and IWaver do approx 18km/h out of the box, the XMOD does about 12kmh as it lacks gearsets in stock form, so dont let that put you off, as the XMODS have an All Wheel Drive option.
You will probably barely ever play with bits again once you have one of these.
You could go with an overland for rougher terrain, or a mini madforce/mini T for rougher stuff, the mini T is a true offroader.