I suggest OpenWrt, for me I have GL-INET MT1300 (Beryl) which is a travel size 802.11ac router with OpenWrt 23.05.x firmware which provides great feature and security, if you want more processing power and/or higher line speed you can even go with GL-INET MT3000 (Beryl AX) which has 2.5G WAN port + 802.11ax WiFi!
Why not a purple? It’s even advertised for exactly this use case
Does physical fw/router bring extra security compared to locked down software firewall and vpn?
IDs/ ips, more robust logging etc, if I didn’t do cyber work in areas I don’t trust I wouldn’t care but data security is important.
Are you going to constantly look at IPS logs hitting your hotel firewall? I’m not sure you’re thinking about your security quite the right way here. Secure your laptop with the firewall in there, block all ingress ports and VPN out. If you’re that much more worried about the foreign country, do like most are doing and bring a burner laptop.
Honestly I wouldn't use either. Stick with a device running OpenWRT. You can pickup a battery powered travel router which will work much better and have a much smaller size and better battery life due to the CPU arch.