Durango is a wonderful place but if mountain passes bother you it would be tough to get there coming from Kansas. Hiway 160 is the main east-west hiway in southern Colorado and it has 2 signifcant passes. Make that 1 significant pass and 1 bugger bear of a pass. LaVeta pass just west of Walsenburg is a high pass that is really not too bad, but Wolf Creek pass between South Fork and Pagosa Springs is plenty tough towing especially coming from the west. People tow over Wolf Creek all the time, but you sure better be on your game and pay attention. I my opinion the worst mountain passes approaching Durango is coming from the north via Ouray and Silverton. I have been towing for many years and grew up around a farm, and I would NOT want to tow from Ouray to Durango if there was any other option. The roads from the east and from the north are both real brake burners to say the least.
About the only alternative if you really want to avoid the high passes coming from Kansas would be to come from Santa Fe or Albuquerque and approach Durango from the south through Bloomfield. JMHO