There are 4 options.
1: Go get more (But you said you can not)
2: The "Extend-a-stay" (No longer made but there is a replacement, MOST RV stores will know what it is) is a very good way to hook in an external tank. It is what I do when I need to use an external tank.
3: A Propane installer can close off your on-board tank and hook you to an external tank or Tanks. for long term parking. I DO NOT RECOMMEND THIS.
4: IN SOME places. ... I was "Stuck" in Georgia unable to move, for like 3 years. Of course I needed propane. Turns out the local Propane service delivers to RV parks and Motor homes. NOTE NOT LEGAL IN ALL STATES. SO contact the local Propane services, or better yet the park and see who delivers THEIR propane and see if they deliver to motor homes.
