I agree, expect that you should better do it in your hotel room or in your car. If you're outside, make sure you are in a safe location, not a busy café or railway station, more like say open spaced area where you can see who's too close.
When you upload to your iPad, you better hope it gets uploaded to the cloud and sync to your home computer with time to spare, before some mugger grab your iPad. Otherwise if you're mugged while in the progress of uploading your photos, you not only lose your technology but also some or all of your photos.
However nowadays, most camera memory cards can hold thousands of photos, so you could still keep shooting until you go home. Even if you used lower storage size, say using a 2GB memory cards instead of using say 32GB memory card, it would help if you got spare cards.
In theory, it makes senses to upload to iPad and sync to cloud while on location, but still keep the originals saved in the memory cards for when you get home, and double check that your photos did get downloaded to your desktop computer. If you were to find out that the cloud goofed (ie: server when down, public WiFi got cut out, etc.,) you would then still need to sync from memory card direct to your desktop.
Rather than having to risk moving (instead of copying) photos from memory card to iPad, in order to free up space on card for more new photos.
In other words: Use the memory card as a back up until you are sure the upload to iPad and sync to desktop via cloud went well.