Where are you measuring this? My Edge JwA tells me my intake air temp and I rarely see that number more than 20* warmer than the temp outside. If I reduced my IAT by 100* my IAT would be 20* when it is 80* outside!Not true. The intercooler is a constant for both cool and warm air, meaning it reduces the temp about the same regardless of air temperature, so your have an advantage to feed it the coolest air possible.
Cooler air is denser air so it is more volume for a given CFM rate. Restriction becomes an issue for a stock air filter at higher HP/Tq numbers because it requires a specified CFM of air to create those HP/Tq numbers. I'm not sure what the max CFM a stock air filter is, but it is considerably higher than most people think. The best set up would be a cowl induction BHAF so cold air can be ingested through that massive filter.
ps... That graph is from PSM. I have that setup on my '98. Cruising at highway speeds it bumped my MPG by about 1. Reduces IAT about 100 degrees across the board.