It was a long time for a human to have been frozen in carbonite. There weren’t a lot of cases of revivals, either, so it was hard to say what kind of shape that Han would truly be in when he ‘recovered’. He needed to be evaluated, regardless, so having someone with a medical background would be important - a sentient and not a droid, of course, would have been Captain Solo’s preference.

The best way to protect Han would be to send him to one of Resistance bases, probably. Leia can control the surroundings there in a way that they she can’t control the private sector.

Regardless, the Captain is just along for the ride. He certainly wants to see Leia again, more than he felt like he wanted anything before.