Heavy duty rubber matting provides a longer lasting solution. Doorways should be at least at least 70 cm wide. To assist the partially sighted, there should be good colour contrast between the door, the frame and the surrounding wall. Clear labelling at a consistent height is appreciated. While carrying is a simple temporary solution, it will always be hazardous and undignified for all concerned.
Alternatives are expensive.
You may care to approach your local government, sports council or charities for grant aid. Floor surfaces should be non-slip especially in areas likely to get wet. A plastic garden chair in a shower cubicle with a curtain, provides a temporary solution. A more permanent facility should have no steps or threshold to the shower tray. The floor surface should be non-slip.