If not, we’ll use it year round on weekends and holidays.

I don't invest there but visit inlaws nearby (45 min away) during the holidays.

Looks like they are held the first Monday of each month (non-holidays).  

The benefit to buying brand new is that they usually come with a 1-2 year warranty, and for a small fee you can add an extended 5-year warranty.The 4th of July holiday is a great time for finding deals on new appliances at the big box places like Home Depot and Lowes.If you are owner occupying a duplex, you can write off expenses for the unit that you do not occupy.

That is pretty much the only thing happening here this week as my team and I are taking some extra time with our families for the Holiday.  

Pay off my mothers house, buy a few 6 units and relax until I die

If you can pickup upwards of 2%, you might as well sit back and relax.

I would looking into to municipalities that with relax restrictions and work to covert a 4-6 bedroom single family to a duplex. 

We pay only €600 rent (roughly 25% off market rate to account for my share in it) for the space we occupy even though the rest is empty most of the time when she is not using it as a holiday home (her prerogative). 

We always have the majority of the summer booked and holidays.