I feel your pain on the weight... and up until the last time that I went, I could not even get a wheelbarrrow.
But my yard bag is a Harbor Freight toolbag (less than $20) with a cheapo Great Neck socket set (3/8) both SAE and Metric witha few extra extensions just in case, a few different size screw drivers both phillips and regular, T20 and T25 torx, slipjoint, regular, and needlenose pliers, wire cutters, 1/2" breaker bar with an 8 inch extension and 19mm and 13/16" socket for wheel removal, a set of magnetic screw driver bits and handle, and cheap HF combination wrench set. for most jobs, this will get me by, but lately I have also added a Dana 35 Manual Hub socket just in case I come across a Ranger/ B series with the hubs. other than that, if I think I need a special part with specialized tools, I will add those as needed for the trip.
AJ