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.

The police will determine if it is abandoned and tow it if necessary, although it may take longer than desired.I suggest continuing trying to contact the tenant and communicate that you will call the police if the vehicles are not removed by a certain date.

You can probably only handle one 100 unit+ property at a time because you will be doing every task from finding the deal, building relationships, negotiating with the broker, finding investors, working with the lender, working with your attorney, communicating to everyone, raising money, more communication, more raising money, completing due diligence, completing unit walks, raising more money, having more investor conversations because an investor can't invest now, then finding more money, then closing the deal, then on boarding your management team, doing asset management, fixing a problem, more communication, and the list goes on while you still only have one property and limited new deal flow since you've been busy doing all tasks previously stated.