I'll preface this by saying that I am a 35 Whelen fan. I've taken a lot if game with the cartridge, and I find it a pleasant to shoot medium bore.
As such, for Iowa, I'd be inclined to build a Whelen on a 700 (for long COAL and for magazine options) with 1:12 barrel, and have it throated for max COAL. Load the highest BC you can, and commence tipping deer over @ 500 and beyond.
That being stated, the 358 N would be an interesting round for those who care to handle the recoil. Along those lines, a 375 H&H or RUM with 300+ grn bullets arent bad long range performers, and they can be had in readily available factory rigs.