That big green yard will help; but it depends on how wide it is, and what types of brush and forest canopy you are surrounded by.
Way back when (1967) I was in the Forest Service (CHILAO HOTSHOTS), we were told that 1 acre (that’s not very big) of class 14 brush generated the same amount of heat that the Hiroshima atomic bomb did, I believe it.
From personal experience; we were on a catline on a ridge above a canyon about 1/2 to 3/4 of a mile wide waiting for our orders.
The fire topped out on the opposite ridge and sent a lot of hot stuff rolling down to the bottom of the canyon; then the opposite slope really got going, just the radiant heat forced us down the backslope of the ridge we were on for protection, remember we were about half to three quarters of a mile away.
Defensive space is great; but always have a GOOD, SAFE, ESCAPE ROUT.
Trust no one, believe nothing. If that little primitive in the back of your head is telling you to get out, it’s past time to GET OUT.
As someone who has evacuated a few times and who has no defensible space, I hear ya. I was just saying that rather than build an ugly concrete home, I would spend the money on a nice stucco home and put in a defensible space. Around here, there are homes that don’t get touched by the fires by doing just that, even as homes surrounding them get torched.