I thought the main difference between "stræde" and "gade" was the latter being way larger, am I wrong?
I'm sure a native would be able to explain better than me, but et stræde is more like a narrow gade, but probably more like an alley in English
"Stræde" is very rarely used at all. We use "vej" or "gade". You should know it exists because many streets are called it, but it is rather archaic and I would never use it in normal conversation unless the street I was reffering to was called it.
Funny - in German, "Straße" is the big one (street), "Gasse" is the small one (alley). I wonder how it came to be that it's the other way around in Danish.