Plant advice for an Essex front garden

Hi! We live in Colchester where the summers are generally very dry and hot and the winters can get pretty standard UK freezing cold (guaranteed long frosts and maybe down to -5ish) - it's making it a bit tricky for me to keep the whole garden alive as it seems I'm always losing plants to these extremes!

This year I planted a load of new front (south facing) garden beds (just as the spring heatwaves hit... Good timing!!) and they've probably had a less than 50% success rate of survival, which isn't great on the wallet haha. So my question is... Any plant recommends that are well known for being properly winter hardy/ safely died back but also can take a proper full-sun pounding heat for months on end the other side of the year?

The happiest plant out there right now is a cool dwarf Verbena (living it's best life), and the lilies are absolutely smashing it too. But doesn't have to be perennials, I'm thinking decorative grasses, even evergreen little trees like palms, all sorts really!

I love going and researching suitable plants but would love to hear your thoughts and favourites!