US electrical extension cord in Europe

We do it. When we moved over we brought a number of lamps and extension cords. I am aware of the wire AWG size and always very careful of the wattage of what I put on them. If you want to plug one thing in and run a number of phone and low wattage electronics chargers off it as long as it is "dumb" and has no surge protector or other electronics in it, and as long as nothing needs grounding I would consider doing it. No way I would do it for high wattage appliances such as a hair dryer, hair straighteners, or motorized anything. When I use mine it has higher voltage but much lower amperage so the wattage is the same. If you do that with a high wattage item, you risk meltage and conflagration. I make these decisions knowing that the wire is only rated 110-120v understanding Ohm's Law, but only for myself and not encouraging anybody else.

I bought an extension cord in a grocery store in France years ago Haul it with me every time. I'm just not into that whole worrying about frying the wires on something over a $6 purchase I can reuse or, leave.

thank you, I will be arriving in Budapest and will look for 240 cord.

The 3-to-1 plugs don't care. They're just metal contacts. However, if you overload them, you could fry something. If you're only plugging in electronics, charges and such, no problem.

thank you, very helpful