I’d say they’re both. A competent government would ensure that we plug any gaps, and they would have already agreed trade deals with major nations that surpass what we already had with the EU in terms of free trade or movement. While I wouldn’t want to see the UK become the new Mexico of the US, I can see lots of British people happily performing seasonal and manual work in the US, and open markets for students to study in both countries.
I’d strongly disagree when it comes to the top two points. They’re just not possible when Britain is such a tiny country. We shot ourselves in the foot when we left, because we had zero leverage against the EU.