There should be no problem in installing a pipe from a boundary meter to your house. There must be no more than a 1mbar pressure drop. This can be calculated using a Mears calculator for PE pipe. You needd the total gas load including boiler, gas hobs, gas fires etc. Convert this to metres cubed per hour, and the length of run allowing an extra 0.5m for every bend. The calculator will then tell you the diameter, Any reputable company that lays PE gas pipe will be able to calc. this for you, it only takes about 10 seconds, but they will most likely want "a drink" for doing so. Alternatively if you give them the job, as you need to be gas safe registered, to be able to carry out the electro-fusion jointing that will be required then they would do this calc for "free". Most companies like this are happy to lay into "trench by others" They will make an approved entry into your house and terminate with an isolation valve and leave for your plumber to make final connections, or do it themselves depending on what you want and leave a thread at the new gas meter position in the correct place for the gas supplier.
Have you also considered, to mitigate the cost of a trench, the run of the trench? Do you need a new water service? Would you like lights along the side of your driveway? It sounds quite long. Do you need power to a shed? Are you thinking of an electrically operated gate and intercom? Droping any of these into the trench as its dug kind of offsets some of the cost.
