You will be fine, I stayed right in had rinn once and near the Ferry terminal and another near where your staying, they’re should be red tuktuks/taxis just off the beach through the night taking being people back, the cost depended on how many people where on it and where you where going.
Otherwise maybe organise something with your hotel, depending on what time you may be getting back.
And hopefully covid hasn’t changed it up too much.
Right okay, well here in Australia you can self isolate in a hotel, might be different there and then there so many different little things with it. But maybe look up on you’re home countries government site for travel too.
Hey check some of the out the posts, on this page so don’t think nong khai border is shut. They only shut two land borders between Thailand/Lao plenty of other posts so jsut search the group.