I would expect the technology to consist of a very small self-contained antimatter reactor, with a warp drive similar to the Alcubierre concept or the warp drive from Star Trek. Warp drive operates by moving the space surrounding the vessel so that the vessel is dragged along with it. An extremely fast warp drive could carry the sleigh near every house within a time zone within the hour and then to the next, and presumably there would be no strain on any component of the vehicle. A rigid system of reins could support the reindeer unharmed, though they'll be nervous unless they've been trained. The reactor could be contained with an energy shield and a spare or several could be carried in the back, and the gifts could be sim

I would expect the technology to consist of a very small self-contained antimatter reactor, with a warp drive similar to the Alcubierre concept or the warp drive from Star Trek. Warp drive operates by moving the space surrounding the vessel so that the vessel is dragged along with it. An extremely fast warp drive could carry the sleigh near every house within a time zone within the hour and then to the next, and presumably there would be no strain on any component of the vehicle. Also, relativity would be a nonissue since the vehicle would remain at negligible speed and within normal space. A rigid system of reins could support the reindeer unharmed, though they'll be nervous unless they've been trained. The reactor could be contained with an energy shield and a spare or several could be carried in the back, and the gifts could be simply constructed with a replicator like in Star Trek and then beamed in with a transporter (also Star Trek.) Advanced holography would leave any tracks and provide something to consume and dispose of the milk and cookies and leave the occasional ashen footprint or sleigh track. Presumably the sleigh itself would be made of some sort of steel or titanium alloy, since if a warp drive is used, weight isn't a concern.