Yes, wildfires get incredibly hot. But the fires essentially always travel by embers or direct contact with fire - your comments about IR radiation seem to imply that IR alone will cause ignition, which is rarely if ever the case.
However, in incidents like e.g. the Fort McMurray fire (Alberta, 2016), this is precisely what happens. One property with a heavy fuel load fanned by strong winds (i.e. plentiful O2 supply) gets hot enough that it causes ignition in a neighboring exposure.
In Ft. McMurray, there were documented cases of an entire 4+ bedroom house being reduced to ash in roughly 5 minutes. The heat generated by that process is easily sufficient to cause ignition in buildings <typical suburban layout> apart.
Here is a story about a bunch of people who survived the Camp fire in Paradise, CA, surrounded by the raging inferno, by staying in the middle of a parking lot: https://www.firehouse.com/operations-training/wildland/news/...