Stop in for a cup of coffee

Going to pour rain here for the next three days, We are taking out 5thwheel to 'Vegas, on Wednesday, a Grand Design rally, to get the thing out from where it is stored, I have to drive on the field. Well, in the dry, no problem, BUT with rain o crap! So I am going to pull it out today, and park it on the street. Wife will not like that but what else to do? The street is a ways from the house...no way to keep eye on it, heck someone could steal the whole darn thing and we would not know...
I will maybe back it up the driveway, will be a ***** but it might work.....
hey question for you.

Lets say someone had a 500-600 gallon tank, they lived in California, but ended up driving one state over where diesel was 50% cheaper, would they get in legal trouble if they brought that back into CA?