What width home can be physically squeezed in is mostly a technical question best handled by home movers. Get a few other opinions. Some movers are more skilled or have better equipment than others. If 4+ movers tell you you can't fit in anything wider than 12' though then it looks like you're stuck with 12'.
If the concern is driving over people's lawns, that concern can likely be easily mitigated with some diplomacy and compensation.
Next time you fly out, set up an appointment with another home mover to look at the width problem and be there on site as he inspects the situation so you can see it from his eyes.