I'm a big fan of not riding my bike when it's oppressively hot. (I know, I'm a rubbish audaxer.) It's sometimes necessary, but I never enjoy it.
You're not a rubbish audaxer at all. The hard part of audaxing is in the head, not the legs, so not doing something that you don't enjoy is entirely sensible. Those that carry on without enjoying it are the ones that stop doing it altogether. I love it and I'm in my 27th season. I also don't like excessively hilly rides, so I never ride anything longer than 100km with big AAA scores.
In my view, a good audaxer is one that thinks through the ride beforehand, looks for possible reasons why the ride might "fail" and have plans in place.
- Might get lost? Bring a map.
- Might get a puncture? Take spare inner tubes
- Might be too cold? Or hot? Bring suitable clothes.
- Might struggle to find food or water? Make sure you carry supplies.
- Might not enjoy it? Do something else.