If they have confirmed in writing they moved out, I would have there stuff moved out to a self storage place ASAP and get the unit up for rent. 

I turned the two-car garage into storage units and will be able to raise rents this winter.

While it will depend on your specific HELOC terms, some HELOCs have an interest-only draw period, meaning if you pay interest for 10 years (or whatever the draw period is), you never actually pay down the principal.So, if i was in your shoes, I'd first check traditional mortgage rates vs HELOC rates. 

Most long term parks require tenants to fully skirt their RV (so look for skirted units) and most tenants who really are staying long term will build an addition, deck or patio, install a storage shed, create a garden, and show other evidence that they have made this their permanent home.With that established, you can underwrite an RV park similar to a mobile home park if the above description of long term tenants is present at the park.

I’m paying for 2 storages and I had to cancel the moving truck for a 2nd time after I already paid for it.

If I were in your shoes I would try to get in touch with as many of those wholesalers as possible so that you can see the deals coming to market.

The Order for the Assignment of Rents was very thorough and basically allows your receiver to step into the shoes of the landlord.

The only questions I would have if I were in your shoes are: why do you need to pay a fee to do this and who does the fee go to? 

I've focused on multifamily and self storage for my active & passive syndication investments but data centers sound like an interesting one.

You can email bills and receipts to a special email address for storage in the cloud and so your bookkeeper can access and enter them.