My Dakota Address http://mydakotaaddress.com is one of many address companies available for travelers who no longer have a personal residence. Once you set up an account with your preferences albeit, mail sorting and delivery frequency to your location you can send yourself over to SD, spend the night in a hotel and head down to the DMV with your hotel receipt and get you very own SD drivers license.
The cost varies depending on how often you wish to receive mail and the size of the PO Box you desire and the staff is very helpful for us folk who haven’t had to deal with titles and they even offer assistance for registering vehicles.
One thing to consider is how SD structures their vehicle registrations as they do require you to maintain current registration for vehicles that are not being used (this may be more common than I am aware of as my state does not require it), otherwise, once you pay the sales tax on the vehicle it is quite inexpensive to reregister each year.