The car will warn you.
(Just as long as the warnings are not broken. Un-coded maybe because you were messing about touching stuff you do not understand.)
If it gets to 170*oC in the UK in the Summer on a track then be sure to come into the pits and open the bonnet and let it cool down. (keep the engine running.)
It will cool it's self even if you switch off, that is why the Coolant shows at 90*oC, that is the coolant, and the oil is a coolant, and the fans will run and the pumps pump.
If you have the correct oil in and the correct amount and get it to 115*oC at this time of the year in Kent i would be concerned.
For you keeping your licence.
Maybe your Octavia 1.5 TSI 150 PS will be better with 0w-30 FS in for your trips on the Continent.
But then you have a Warranty from the Czech / German car maker, so maybe stick with the recommended VW508 , so 0w 20 FS IV.
And have the Servicing done at a VAT Registered place using the Factory Approved Fluids and Parts.