We do the work, you earn the daily payouts as the renter pays.We specialize in long term rentals so its pretty common have one renter for months at a time.Based out of South Atl, Ga, we house and operate your vehicle out of our Club House where we handle the maintenance, daily communication with renters, and paperwork! 

If rents are declining, to keep the property full at current rates I would keep the rate flat.If they're good tenants, charge them a short-term rental premium but dont' give them a huge increase for the 6-month lease.In these cases where it's a 1:1 tenant/landlord renewal, it's best to communicate with each other and reach a win-win

I'm thrilled that we've grown to this point in our portfolio, but we are now up to 10 single family homes, and with other (more than) full time jobs, we are desperately looking for some help from someone that can help us track rents, walk throughs (property upkeep), etc.We have done an excellent job up to this point, but it is not sustainable, since we travel for work, and our tenants need more communication/attention.Any suggestions/thoughts here?

Relationships and communication are EVERYTHING.

Communication, process and certainty of execution are key. 

Smart, excellent negotiator, great people instincts, communicates the way I want.It does not matter what car they drive, what they look like, or the bells on the website.

Plus it integrates with your calendar so the communication between you and your cleaner is minimal as they just know when they need to get in and clean. 

Make sure you have an open communication with them about this since they will probably be able to provide you good perspective on the situation.

If when communicating you show that you are aware of the law and your rights under the law you may get a better result.

If after the specified time (in CA it is 3 days), the tenant continues to violate the lease, then an unlawful detainer is filed in your local court.I strongly suggest trying to work with the tenant and communicate for an amenable situation as @Theresa Harris suggests.