Since you have a Roadtrek, your LP tank is mounted under the center rear of the chassis? It also should be a small(no more than 10 gallon ASME tank). Since you cannot find a Purger locally or even hundreds of miles away, I would just have the tank removed. Just 4 bolts. Then you have 2 choices. Find a purger for the loose tank or just purchase a NEW tank at your final destination. Your smaller tank would be about $700. IF NEW, Matson may let you ship the new tank inside the RV, or if certified by the seller, allowed to ship installed on the Roadtrek. We have had to remove ASME LP tanks from large motorhomes, because they had liquid LP still in them to use in indoor RV shows. The fire marshal allows LP tanks to be drained(NOT purged) of any liquid LP. and NO vapor comes out when valve opened. IF we get one inside the Indoor facility and the Fire Marshal finds one(VERY RARE for this to happen), we have no choice but to drop the tank and remove from the facility. Doug