I’m surprised it took me as long as it did to discover that there’s an accessibility alternative for dragging. In System Preferences, visit Accessibility > Pointer Control > Mouse & Trackpad.
Click on Trackpad Options, enable dragging, and choose three finger drag from the pop-down.
I’ve been using three finger dragging for about a week now and it’s been a vast improvement over my attempts to drag items the normal way. Yes, I still end up running out of trackpad room as I always do, but using a finger from the other hand to nudge things where they need to go does the trick for getting my dragged items to their destinations.
I am using this almost entirely in Finder, although the same approach should work for moving words in a document or views in IB.