I did a quick check on price per day comparing DIA with one in Denver and noticed that one of the SUV's (Rav 4) in town was significantly cheaper than the same vehicle at DIA. However, the rest of the larger SUV's weren't significantly different. Maybe there are additional fees that the airport location hits you with.
The following is just something to think about. I'm not trying to discredit any of the above advice.
As far as hunting from something other than a 4x4 of some sort goes............you're are taking your chances. Note that the fella that made it in a Honda Accord said it was dry and windy. When I was there it rained some everyday and we left just before a big storm along with a tornado came through. So, yes, it can be done with a car if its dry, but in my mind that is a big risk to take if your flying into Denver from the east coast then driving from Denver to north central KS.
Also, mail routes may indicate a better road, but in one short hunt I saw multiple locations with a row of mailboxes at the end of a "gravel" road. The route from there back toward the homes that those boxes serviced and to the location I wanted to hunt was 2 or 3" of sticky snot that would put you in the ditch or ball you up so bad you weren't moving.
I've seen this same type mud in Nebraska and Eastern MT, and it can end your day quickly. If it's dry.....no problem, but if it gets wet............your up a creek without a paddle.
