I fly to sits and try to travel light even typically.
The only extra thing I’ve been bringing for sits is a dishwashing sponge, for hygiene’s sake.
I’ve just bought one of these and will bring it on my upcoming sit:
It’s very light and packs into its own bag, roughly the size of a hardback book.
Normally for any travel, I bring a travel extension cord, because I carry multiple devices and telecommute. Mine looks like this, with three outlet plugs and a USB outlet (the cord wraps around itself and plugs into one of the outlets, so it’s compact.)
I’ve got it out, because I’m about to travel and I test my cords before trips. I’ve had ones fail before and I don’t want to risk it for telecommuting.
I also always bring flip flops for any trip. I wear them as house slippers, because I don’t wear shoes indoors. And I use them as shower shoes, so it’s not slippery and I don’t risk picking up say a fungus from anyone’s shower, including at hotels.
I wear a knee-length hoodie on flights. Good for eye coverage and warmth when sleeping. Also serves as a robe when I arrive. And in a pinch when I go places where I need a head covering and modest apparel, I’m good.