LH F is generally well regarded and would get you into Europe. You’d probably have to book J and change it to F if availability opens up 15 days out. There are a number of good destinations for culture within the EU say Germany for a few days (Berlin has a number of historical parts although all bar one are limited to post 1945).

Italy has many options, though it’ll be hot and stupidly busy, not sure how busy Lake Como at that time would be but that might be worth consideration? For a more relaxing downtime. Also easy to get around in Europe by train - although beware Italian trains changing platform last minute.

For me I’d personally head to South America though no idea who’d get you there in F. And you have to be careful in places. You could just about get a Galapagos trip in there, which would mean some limited beach time ... more wildlife orientated if that’s your thing.