Preparing for Alpine riding
I don't have experience riding at moderate altitude (1000-2500m), but do have experience mountaineering in the French Alps (>3000m) and Himalaya (up to about 5000m).

Going to over 2000m altitude is not trivial, even for people in good shape, and can have some adverse effects. It's not something you can totally ignore. Although if you are fit and have experience hiking at similar altitude you will definitely notice the relative lack of oxygen but avoid any serious issues.

The most important thing is to drink tons of water, which helps with some of the immediate physiological effects of working at altitude.

As your accommodation is relatively low you will have a chance to recover each night. The mountaineering mantra for acclimatizing is 'climb high, sleep low'.