I've been in many an RV park which ALL sites had metered electric no matter what the size of the RV. I feel that's fair. Someone in a 16ft pop up wouldn't use anywhere near the electricity as my 40ft all electric 3AC Phaeton did.
I've been in many parks that charged metered electric rates for weekly or longer stays, but most build the charge into their standard rates for nightly stays.
I have never seen a park that metered overnight stays. Who would handle the meter reading on a late arrival/early departure. How would you handle payment? Most people wouldn't like charges appearing on their credit cards after they have left and, believe it or not, some people still pay cash. Would the park have to take a cash deposit and send the customer back the balance after deducting the electric charge? Or do you prohibit people from leaving until they settle the power bill, in effect meaning someone would have to be on meter duty 24 hours a day, likely costing more than you would ever collect. Besides the fact it would be a logistical nightmare to read, record and charge the guests on nightly stays, the costs almost always even out. Yes, the all electric coach may use more electricity than a popup, but the popup is much more likely to use the park's restrooms and showers. It ends up being a wash between the two. (that is unless you also want pay showers).
While you may never have seen one, they do exist. The last one I was visited was Lock30 in Ohio. It was kind of on the honor system. I was given a meter read sheet upon check-in. I wrote down the meter reading when I arrived at my site, wrote down the meter reading after I unhooked/broke camp and I turned that sheet in and paid for my usage before leaving the park. They had my credit card and billing info on file from when I paid for the reservation, so it wasn't like I couldn't get out of paying at least something. I don't know how they handled all the situations you mentioned & it doesn't matter. My response was to the member who asked about fees based on RV size. I just noted parks DO have metered electric for even overnight stays & how it was fair to base that charge on usage.
As I recall, an Escapees park charged that way, I got the paper when checking in to write down the meter, and then write down the departure number, paid the bill when leaving. Not a big deal and it was a very reeasonable electric charge.
Escapees parks only charge for metered electric on the monthly rates. Daily and weekly rates include 30 amp electric with an extra $2/day charge for 50 amps.
I can't wrap my mind around how metering electricity for an overnight stay could possibly benefit either the park or the customer. How much is the bill for a night? From experience (owning parks) it can't be more than $2 or $3. If paid by a card, there is a transaction fee to account for, on top of the 3% card fee. The customer has to fill out the meter reading sheet, the office has to calculate the charge and then collect the money. That's a whole lot of moving parts for a dollar or two. In my opinion and experience, trying to chase down nickels and dimes costs the business dollars. A simple fee structure combined with providing the best services you can is the easiest route to a successful business. Fees not commonly seen in the RV business, such as fees based on rig length or daily electricity charges are likely to be counter-productive in the customer service world.
I agree, daily electric billing complicates what should be a simple process for little if any gain. Charging by length works ok in the boat dock rental business where length can affect the number of vessels that fit in a given space, but RV park sites don't work that way.