It's rare to have no wind on North/South on I43 in WI between Milwaukee and Green Bay. 30 mph head winds are common. We go that way a lot into Door County. It's equally rare to have the wind pushing us. It seems when we head north it's a northerly wind, and a southerly wind when we head home.
That said it's only a 22' 4500# trailer, I get about 8.5/9 mpg heading into the wind. I get 10/11 with no wind. Occasional downshifts when heading up a hill in the wind. The dreaded "P" rated truck tires (Not the same as the "P" rated tires on your cushy Buick) don't wobble or sway. If I had a 30' trailer, then yeah, LTs are called for.