You're thinking of Arabia.
I don't see that sailing right across the Mediterranean, up the Iberian Atlantic coastline, then across the Bay of Biscay to North Central Spain is less fantastical than tracing the usual route up the River Danube.
Could have been and was done without much admixture along the way, hop-scotching via Crete -> Sicily -> Sardinia -> Iberia. The establishment of the Iberian "entrepots" has been theorized as part of the chalcolithic expansion in search of new sources for copper (with the Balkan copper mines being worked out). If M269 was a smith or prospector, he would have had special skills. Or he could have been a trader (establishing a "trading post"). While no copper mines from before 3,000 BCE have been found, that doesn't mean they didn't exist. If a trader/smith, he needn't have mined it, but could have traded finished tools for raw ore and other items.
Vila Nova de Sao Pedro was "ground-zero" for megalithism and is within reach of many copper and tin mines in western and northwestern Iberia. It is also on the way to Cornwall, where copper and tin mining became the likely source of wealth that paid for Stonehenge (from c. 3,100 BCE).
The idea of R1b originating in an ice-age "refuge" south of the Pyrenees has been disproved.
Immigration up the Danube (or across the Carpathians) is possible, but the Yamnaya CHG-component (Yamnaya = Khvalynsk + CHG) might not have been present in Sredny Stog or Suvorova, with their expansion that collapsed "Old Europe" and opened the lower Danube dating from c. 4,000 BCE. Yamnaya don't show up at the Dnieper Rapids until after the collapse of "Old Europe" - they could have been the force that shoved the Suvorova off the steppe. Any Suvorova leading-edge would have had to transit already settled lands (Global Amphora, for instance).
But (Iosif Lazaridis):
As we mentioned in Haak, Lazaridis et al. (2015), the Yamnaya are the best proximate source for the new ancestry that first appears with the Corded Ware in central Europe, as it has the right mix of both ANE (related to Native Americans, MA1, and EHG), but also Armenian/Caucasus/Iran-like southern component of ancestry. The Yamnaya is a westward expansive culture that bears exactly the two new ancestral components (EHG + Caucasus/Iran/Armenian-like).
https://indo-european.eu/2017/07/so...admixture-and-archaeologists-are-catching-up/
Which returns to a two-wave theory with the first wave of "newcomers" hitting Iberia, with assimilation, but then being overrun by a stronger second wave, with site-abandonment and population-replacement (of y-dna lineages), but
not necessarily language-replacement.