I just installed a 300 foot propane line and got it inspected. 1/2" OD line good for 200,000 BTUs. You need a hi-low system. 10 PSI regulator at the tank and a 2 PSI regulator at the house or shop.
1/2" OD plastic-covered coppper made for direct burial propane at 250 feet is good for 222,000 BTUs.
Just pay attention to any copper you buy. Some is sold by the ID size and some by the OD size.