Your best bet is to go through the stance and fitment thread over on vwvortex (
https://forums.vwvortex.com/showthread.php?5826956-JSW-quot-Stance-quot-quot-Fitment-quot-thread/page39). Keep in mind most of these rides are lowered either on springs, coilers or bags. Finding stock photo's on 19's is a difficult needle to find in the haystack, but it's a good read and chance to learn about the fitment (offset, width, spacers, hub centric rings etc.) characteristics of our long roofs.
The biggest obstacle I see is matching the appropriate offset to the width of the wheel you want, which I would guess is 8-9". The second issue you might run into is tire profile, with a 19" wheel you might be forced to run a smaller sidewall height like a 35 or 40. This looks great, but can get expensive fast since it's higher priced tires and they're more susceptible to road imperfections like bridge joints on highways or pot holes which in turn makes you're wheel more susceptible to bends and cracks. If you neglect any of these things you might find you rub even with stock suspension on 19" 's when you turn the wheel lock to lock or take a turn with a depression in it at speed. Not trying to dissuade you, any long roof that eliminates the gap and fills the wheel wells is a thumbs up in my book. To each their own.