thesilverspear - yeah, I've arranged to watch a few lessons. That's another thing that I'm slighty worried about - should I switch, then choose to return, perhaps I might be greeted with a less-than-warm welcome.
Grace - sometimes I've just had to grit my teeth and get on with it! When the paddock gets extremely flooded, we've had to go on hacks to compensate. Snow and ice just make lessons impossible as the surface is frozen and hard on the horses for anything more than a walk, while the trails freeze over and become hazardous. So yes, that will be a major factor in my decision.