Leave it 1/2 full - there may be times when you need to run off of the tank (water main break in the park - been there, done that!)
If the park is served by municipal water, just run it through, you don't need to bleach it. In fact, since you have six months, this is a good time to run municipal through several times. Also make sure to back flush the black tank 2 or 3 times during your stay. And boil a few pots of water for pasta and dump down the grey tank.
The ZTE Mobley can be 'finicky' at times.
We had (Decided to scale back on Mobley, as we added other data plans to other services. So back to only one ATT Unlimited Mobley device.), two Mobley's for quite sometime. One of the Mobley's Sim we put in our Unite Explore 815 device which is MIMO capable, attached to a Roof Top magnetic Mobile Mark MIMO antenna. The other, we kept hooked up via the OB2 power converter combo.
Many times the Mobley via OB2 powered connection, would reflect via 192.168.X a good signal. When in reality, it was 'a signal'. (And no, it would not be very helpful for data download usage:)!). At the same time, the second Mobley Sim in the Unite explore, with roof top dual MIMO Mobile Mark antenna feed - would reflect a lower signal strength - while at the sametime yielding Speednet Download Speeds 2-3 times faster then the Mobley with now roof top antenna, let alone, MIMO.
So while we had both still working for us in our arsenal to the cellular data connection world - we'd normally ignore the Mobley's info. Only tapping into the Mobley if we detected cellular tower network traffic de-prioritzation, while over our GB usage for a month. (Maybe three times, I think, I saw a difference via Mobley vs Unite Explore with the same sort of SIM cared for out other Mobley - the bulk of the time, the Mobley SIM in the Unite Explore - had been our Download Speed champion...
Hope your move to the next location get's things flowing again for you:)!