Depending on the tools and skills you have I would think you could do the standpipes and dummy plugs in an afternoon (I have not done them, so this is just a guess) since they are just under the valve cover. The STC is more like a one day project since you have to pull the turbo to get to the STC on the HPOP. It all depends on what year you have though... some high pressure oil systems are different depending on the year.
Do you have a Edge Insight or something to monitor your PIDs? you could look at the IPR% demand and ICP pressure to see what is going on. What you really need to do is an air test to see what is leaking and where. Don't start throwing parts at it until you have it diagnosed.
Considering you are in a hotel parking lot, you may want to look into the local Powerstroke chapter to see if they can recommend a local shop, or else you may luck out and find someone with some tools and time to help.