I've never used ErWin, but someone did mention once that it cost 7 Euros for 1 hour's access...which apparently is enough to download your cars's factory options, ie. build codes.
However, there's a seller on ebay who can supply the build codes for about 3 Euros.
Search "skoda vin decoder" on ebay to find this listing
https://www.ebay.co.uk/itm/224631127243
You might also want to take a look at the following website which shows the Skoda approved rim sizes for the Superb MK3
https://eshop.skoda-auto.cz/cs_CZ/alu-kola/c/alloyWheels?sort=priceAsc&q=%3AscoreDesc%3AcarType%3ASuperb%2BIII%2B%282015-2024%29&show=Page#
Wheel sizes for Superb MK3 (16" wheels won't fit the Superb MK3 2.0TSI 272HP/280HP 4x4)
6.5Jx16 ET41 5/112 57.1 (215/60R16)
6.5Jx17 ET41 5/112 57.1 (215/55R17)
7Jx17 ET40 5/112 57.1 (215/55R17)
8Jx18 ET44 5/112 57.1 (235/45R18)
8Jx19 ET44 5/112 57.1 (235/40R19)
You might also want to look at the car's CoC (Certificate of Conformity) which shows all the Skoda approved wheel sizes.
Here's a couple of suggestions for the 17" tyre size. The 18" option won't ride as well as the narrower, higher profile 17" option. The 17" option will also be slightly more economical, ie. slightly better fuel consumption.
Continental AllSeasonContact 2 215/55R17 94V (Euro label B B 70dB) (3PMSF)
https://www.camskill.co.uk/m140b0s8825p220589/Continental_Tyres_All_Season_Car_Continental_Conti_All_Season_Contact_2_215_55_R17_94V_TL_Fuel_Eff_%3A_B_Wet_Grip%3A_B_NoiseClass%3A_B_Noise%3A_70dB
Vredestein Ultrac 215/55R17 94W (Euro label C A 69dB)
https://www.camskill.co.uk/m54b0s1714p210552/Vredestein_Tyres_Car_Vredestein_Ultrac_215_55_R17_94W_TL_Fuel_Eff_%3A_C_Wet_Grip%3A_A_NoiseClass%3A_B_Noise%3A_69dB
Bear in mind that even into the early 1990's, some of the big Jaguar cars used 215/70R15 tyres...so the much lower profile 215/55R17 is going to be able to provide far more lateral grip than that tyre could...plus thirty years of tyre development.
Outside diameter of tyre
215/70R15 682mm (2.0% bigger outside diameter compared to 215/55R17)
215/55R17 668.3mm
Big Jag from around 1991 perhaps with 215/70R15 tyres
https://en.wikipedia.org/wiki/Jaguar_XJ#/media/File:1992_Jaguar_Sovereign_4.0_Rear.jpg
A non-standard 16" tyre option could be 205/65R16. Apart from the superb ride comfort, even better than 215/55R17...this tyre size fits in the spare wheel well without raising the carpet. The 205/65R16 tyre size could be fitted to the standard 16" rim size, ie. 6.5Jx16 ET41 5/112 57.1.
Outside diameter of tyre
205/65R16 672.9mm (0.7% bigger outside diameter compared to 215/55R17)
215/55R17 668.3mm
Vredestein Ultrac 205/65R16 95W (Euro label A A 70dB)
https://www.camskill.co.uk/m62b0s2785p210548/Vredestein_Tyres_Car_Vredestein_Ultrac_205_65_R16_95W_TL_Fuel_Eff_%3A_A_Wet_Grip%3A_A_NoiseClass%3A_B_Noise%3A_70dB
7Jx17 ET40 5/112 57.1 Ratikon alloy rims (from Kodiaq but same specification as Superb MK3) (11.1kg) 565071497A 8Z8
https://eshop.skoda-auto.cz/cs_CZ/alu-kolo-ratikon-17-kodiaq/p/565071497A+8Z8
Here's four links to Michelin Primacy 4+ tyres in the standard 215/55R17 and 235/45R18 sizes, and slightly oversize 225/55R17 and 245/45R18 sizes...all with W (168mph/270km/h) speed ratings and XL (eXtra Load). They all have B A 70dB Euro labels. The Michelin Primacy is a summer touring tyre, so will give a smoother, quieter, more refined ride than an UHP (Ultra High Performance) summer tyre such as the Michelin Pilot Sport. The summer touring tyre will also tend to have a longer tread life than the UHP summer tyre.
Outside diameter of tyre
215/55R17 668.3mm
225/55R17 679.3mm (1.3% bigger outside diameter compared to 235/40R19)
235/45R18 668.7mm
245/45R18 677.7mm (1.1% bigger outside diameter compared to 235/40R19)
Michelin Primacy 4+ 215/55R17 98W XL (Euro label B A 70dB)
https://www.camskill.co.uk/m54b0s1714p210232/Michelin_Tyres_Car_Michelin_Primacy_4%2B_215_55_R17_98W_XL_TL_Fuel_Eff_%3A_B_Wet_Grip%3A_A_NoiseClass%3A_B_Noise%3A_70dB
Michelin Primacy 4+ 225/55R17 101W XL (Euro label B A 70dB)
https://www.camskill.co.uk/m54b0s466p210230/Michelin_Tyres_Car_Michelin_Primacy_4%2B_225_55_R17_101W_XL_TL_Fuel_Eff_%3A_B_Wet_Grip%3A_A_NoiseClass%3A_B_Noise%3A_70dB
Michelin Primacy 4+ 235/45R18 98W XL (Euro label B A 70dB)
https://www.camskill.co.uk/m61b0s2057p210225/Michelin_Tyres_Car_Michelin_Primacy_4%2B_235_45_R18_98W_XL_TL_Fuel_Eff_%3A_B_Wet_Grip%3A_A_NoiseClass%3A_B_Noise%3A_70dB
Michelin Primacy 4+ 245/45R18 100W XL (Euro label B A 70dB)
https://www.camskill.co.uk/m61b0s315p209227/Michelin_Tyres_Car_Michelin_Primacy_4%2B_245_45_R18_100W_XL_TL_Fuel_Eff_%3A_B_Wet_Grip%3A_A_NoiseClass%3A_B_Noise%3A_70dB