Osa peninsula - where to stay/how to get there

We are a group of 10 - two families, kids aged 7 - 19, coming to costa rica for 10 nights in late June. We will rent two 4x4 vehicles. Flying in/out of SJO.

Right now our plan is 3 nights in La Fortuna, then drive south for the remaining nights. We would like to split it up between Dominical/Uvita and Osa but the getting to Osa part is feeling overwhelming. Our kids are experienced travellers and are used to doing long car rides mid trip so that will be fine but I know the roads aren't what we are used to.

Is it possible to day trip to Osa area from Uvita? Are there family friendly lodges that you recommend? Can we safely leave our rental cars somewhere ? I've read lots of posts but still feeling overwhelmed.