Gosh you're lucky with no accidents Mum2Ella!
We always go out with spare knickers and often spare skirt or shorts.
Our issue is that Charlotte doesn't mind being in wet knickers

so she has no great motivation to get to a toilet.
It does mean we avoid any tantrums but she also just treats pull ups like nappies...expensive nappies, that is!!!
We are nowhere near training at night but I have been told that when you think they're ready it is a good idea to wake them to go on the toilet before you go to bed so they don't have to stay dry for the whole night.
Charlotte has decided she doesn't need a day sleep any more so we don't have to worry but we still put a nappy on her while she was so she would hopefully have a longer sleep.