Sleeping arrangements for a 10 mo while travelling

We'll be going abroad with our 10 mo, and staying with family for 3 weeks.

What were your sleeping arrangements like for long travels?
Would a pack & play work for 3 weeks? I'm thinking of buying one in advance there for him.

The space is not child-proofed so we definitely do need something with 4 walls.

Thank you!

(Any advice or must-haves while travelling also very appreciated 🤞)