Moving supply is costly.
Gas. Move 3m you can not use the DNO fuse to protect your meter tails, you must buy a switch fuse of 80-100A capacity which consists of a double pole isolator & BS1362 fuse holder (& fuse!). Then run say 25mm SWA 3-core to the new consumer unit location. Note some DNO will not let you use their board to house your switch-fuse, somewhat ridiculous considering some are huge and modern cutout & meters are tiny. A solution is to buy a waterproof external enclosure or another meter cabinet. If you have Economy 7 you either need another switchfuse for the E7 supply (using the DNO teleswitch timer & contactor) or use a single switchfuse and separate timer & contactor you provide & fit elsewhere.
A temporary location may be a separately chargeable job, unless the move is some distance in which case it may be priced into their survey.
The job will be done as "grid-side" and "post-grid" re two different people turning up, the days of =A3250 in the hand are gone in most places and they do keep records of locations (not re meter people, but if something goes wrong re a street problem and they need to access your meter - particularly gas).
Sewers etc. I assume there are no public sewers or 24" railway drains etc in the location. In which case they have their own requirements which can extend as far as paying to have them moved or using lintels to span over them so no load re subsidence parks on top of their drain.
Other factors likely to change the cost: If anyone elderly living there they must be able to access the ECV - Emergency Control Valve - for gas. This can mean you get a free meter move typically from an inside inaccessible cupboard re height to outside so at least someone can access it. That can save about =A31000 in the worst case scenario (elderly aren't good at digging trenches :-)
I have no idea what they do where the electric supply is a loop-in supply, that is to say where you receive a supply cable and the DNO runs another supply cable from your cutout to the neighbour. This "save a bit of copper" technique is no longer permitted, nor joints under driveways (and some take that to mean anywhere in the most extreme). I suspect they have to run a new cable to the street for the neighbour if you want to move the cable - not sure how that is charged.
So it is not cheap. Timeline is also a bit long, so plan accordingly.