So, I'm going to speculate that, if you want to use the condo 3-4 times a year, it's probably for short vacations, whereby the property will be more investment than lifestyle for you.

Just for the accidental times when they have the bathroom heat off because its hot out and they go on vacation for 3 weeks with the door closed and the temp here drops under freezing.

And when we moved from our 3br condo to a SFH in Colorado Springs, we turned the 3br condo into an MTR as well.In between, we also partnered to buy a duplex in Colorado Springs and just recently a vacation rental/STR in Mexico, but this was years after that first one. 

I don't love letting folks view when an existing tenant is there because it is not a controlled environment, however if you have had a recent inspection of the property and you know it shows well and the tenant is amendable then "GREAT".I would add that since your tenant is vacating early, they are still financially responsible for the lease until end of term.

She could then have a domestic violence reason to vacate, leaving you with just him living there? 

Primary reason for wanting to do STR is because I'm interested in gaining hands-on experience with this strategy so I can apply it towards longer-term goals in more traditional vacation markets. 

You could have called their office to see if they were on vacation, but most realtor would still check calls while they are away or change their voice mail to tell them who to contact.

In general, travel for business(education, networking) is deductible if you are already in a trade or business(I.E. have a rental, flip).There are unique rules to deduct foreign travel costs.attendees may have a more difficult time writing off the cost of the trip if they add significant vacation days(no business) before or after the trip.However, you can plan properly to make the trip 100% deductible.

i'm in MA and used to own a vacation rental in NH!

(Max vacated rents - your monthly mortgage payment) = +/- net cashflow.