Short floorboards -- do extra wide baseboards exist?

Often people put down quarter round at the bottom of the baseboard to get extra coverage, but I don't think that will work here. You could put panel wainscotting against that wall to move the wall out closer to the edge of the boards. If the panel is thick enough, or spaced out enough, it should work. Brad

Make them. 1" is easy enough to cover, 2" it getting tricky. Don't think of a premade baseboard, but think of a two or three piece trim. Put a flat board, say a 1 x 4 against the wall. Add a decorative top molding, add a quarter round base molding and you have custom baseboard that people pay a lot of money for.

If you have very high ceilings or a large room, you can go even wider with the base trim. Some older houses had 8 or more inches on the baseboard. The 3" clamshell is relatively new.

A real lumber yard will be able to mill what you want or have it done. If you don't need to match something exactly, likely it will not be too much. If you want to match some non-standard existing molding, it can be done, but at a price.

According to :

Do you mean the (to be) finished flooring will be short? Or the subfloor? If the latter, you can cut off the floor boards in a straight line and slide in a strip of new flooring. A room accent.

Otherwise, build up existing molding will do the trick.

The perpendicular strip of flooring at the end sounds like probably the best idea; you could build up a thick molding but it might look funny unless you do it all the way around. Installing even one strip of oak flooring can be an adventure depending on your carpentry experience and moxie. The key to the flooring install is to cut a nice straight line. Use a circular saw and a guide. The wall (with existing molding) could maybe be your guide, or you might have to nail or screw down a guide board.