Moving across is a file operation. Get the site onto your own machine, whether that is a folder of HTML, a build directory or a single page, and nothing about the destination needs configuring first.
Then drop it in. A single page goes up as it is, and a folder goes up as an archive that unpacks and serves at its own subdomain, with client-side routing working the way it did locally. The free plan takes 25MB a file and holds 10 active links, so a small site can move before you decide anything.
The part that needs planning is the address. A NudgeHost link gets its own slug, and a subdomain you have already circulated will not follow you. Put the new page on your own domain and point the old one at it. Custom domains sit on the Pro plan.