For any "microwave" link to work you will need line of sight, a clear view to the other location.
However for a real microwave link you require a licence just like the big telco's.
In lower frequencies you do not need a perfect line of sight (for example 900mhz) but those require a licence + the speed is far lower.
The lower the frequency, the longer the distance and less hinder by obstructions, but also lower speed.
Most (privat) long range wireless connections are in the (licence free) 5ghz band, to have less interference of the 2.4ghz routers who everyone have at their home. With proper line of sight, a link of +10km is relative easy to make while still using routers of below 150e each.
The current equipment can offer speeds up to +-400Mbit, models are coming out on the 60ghz band that can do gigabit speeds but they are hard to aim and the distance is max 1km before the speed will drop.
To get a indication if a link is possible you could use https://link.ubnt.com/
but the site is unaware of any obstructions.
It will also show the "fresnel zone", that area should also be clear of any obstructions to get the best out of a link.
So, if you have a clear vision of another location with internet, a link between the two is relatively easy to create.
The offer from Virus sounds like a very good deal for holidayhomes, no two year contract like ote, and no hassle with getting a phoneline (if even possible)