If you're looking to pull up to a continuous 100 amps of 240 volt into a sub-panel 275 feet away, 1/0 AWG copper cable, with a proper local ground. If you are going to be driving over the run and aren't placing it under a concrete driveway or walkway, use 1-1/2" to 2" conduit buried 18" to 24" deep. And whether or not you use conduit or direct buried cable, be damned sure back fill is free of any rocks. Personally, with the cost of electricity anymore, if this isn't going to be a 24/7 need, I'd be thinking about Solar with battery storage, or a good size generator installed at the shop.
Phil
