I’ve seen people at big conventions carry multiple dolls (in a standing position) inside a small rolling crate. Like the type you use to carry papers in big offices. I thought that was neat. Definitely convenient looking, especially since you won’t get weighed down. I’ve never tried it though. I’d be concerned about rolling the cart into strangers lol
I bring the doll in my Iplehouse carry bag to the con, but at the con I usually just carry them in my arms. One of the characters I cosplay is a doll maker so that works very well with the costume! I have a tote bag that is long enough my 1/3 dolls can sit in it. I used it last year but I misplaced it for this year. I don't think I would bring more than 1 doll around with me at a con unless a friend was volunteering to hold it. That's just way too much. Carrying 1 doll is already too much.
Something like the volks uchinoko-kawaii tote bag works really well if you want to carry your doll hands-off while still having it be easily visible. Personally I didn't have $100 to spend on a tote bag, so when I brought a large doll to a local convention I made my own version of the volks tote from scratch with some fabric and thick plastic sheeting from the fabric store. It's pretty much just a bunch of rectangular panels, so it's pretty easy to make for a beginner in my opinion. It was my first ever project on a sewing machine and it came out okay! Granted I did simplify some things, for example the side and front panels don't zip down on mine, but I found that to be an unnecessary feature. Although in hindsight I think the open top is a design flaw as a lot of dust/debris got on my doll by the end of the day. If I ever re-do the bag I would add a panel on the top that zips open/closed to avoid that. Maybe pockets at the back too to make it multipurpose. If you wanted to make it on a budget and way easier with fewer steps, I would recommend buying a white, cheap (but thick/stable, rectangular and preferably canvas) tote bag and cutting out the front panel and replacing it with plastic sheeting.
I forgot to mention that I've also got an open topped crafting tote that is rectagular and devided into six equal-sized sections inside - it's just the right height for 1/6 (Yo-SD, LittleFee, Petite Ai) sized dolls to stand looking out of each section (a bit of a sqeeze with the slimmer ones would allow for two in each section. It has lots of pockets around the outside for small items like clothing, accessories, or pens, coins, cand other potentially useful bits and pieces. I've used it a few times, and it's very useful, but tend to forget that I have it as I tend to think first of taking larger dolls with me. Teddy
Because I am a minimal lazy person. I bring one bag (either transparent bookbag meant for a pet, American girl doll carrier, or cloth tote) and I bring only one doll that I will carry in my arm that will go in said backpack because I am a distracted shopper.
I just got special hard carry cases meant for fishing rods, they come in several sizes from 70x20x13 to 120x20x13. Just like plastic suitcases, only long and narrow. Inside there’s velcro straps to safely secure the doll. 80 cm case for 70 cm doll, 70 cm case for 65 cm doll. I wrapped my dolls in a bath towel first to protect from velcro, then strapped them in, zipped the case. I’m dragging my dolls across 3 countries right now, they are safe and comfortable as far as I can tell. No complaints from the luggage department. While the cases perfectly solve the problem how to get the dolls to the convention or anywhere else they do nothing for carrying the dolls during the convention. Cases are not transparent. And unfortunately I can only carry my crossbody handbag with keys, wallet, phone, tissues for longer periods. So I plan to take my dog pram. Got it for actual dog but why not.
When I was at NYC Doll Con, I carried my dolls in a clear tote that I received for free at a conference. It was the perfect size for one 1/4 doll and one or two 1/6 dolls. It was small enough not to get in the way while walking around and made it easy to just reach in, grab a doll, and then put them back when I was done. It also had the bonus of letting me show various postcards and stickers I acquired at the event by placing them behind where the dolls sat (next year I may bring tape so I can secure them to the back panel!). I really recommend clear totes! They're actually becoming easier to find these days since various concert venues ask that you use transparent bags. Here's a photo of my bag on the second day of the convention. Spoiler: Photo