A 100A feed to a single car garage is a little overkill in my opinion. Save yourself some money and use #4 aluminum Teck cable for a 60A feed to your garage. You can run it exposed on the ceiling or walls of your basement
(no drilling) and bury it directly without conduit. Very tough, durable stuff. That will easily run your 5kw heater, compressor, welder and what have you for half the price.Check Facebook Market Place or Kijiji, it’s commonly used for temporary power on large construction sites so long runs are easy to find.I would offer half of wholesale price of new cable.