Honestly unless the weather window is amazing I wouldn't spend the time in the cascades unless you are ski touring. If you are ski touring, it would be perfect time of year for Isolation Traverse, Ptarmigan on skis, or Forbidden Traverse
I'd echo Banff for ice, JTree or Red Rocks or Smith for rock climbing. Moab for a week of crusher mountain bikling. Indian Creek if you are up to it. Sierra for melting-out-but-probably very cold higher elevation scrambles