I guess it would depend on what the runtime error says. Sometimes it's more descriptive. I thought it would say if you ran out of vram but I may have remembered incorrectly. However if removing the objects let the project run again that may be the issue.
The editor itself uses vram too if any layout tabs are open. I had a pc for a bit that had a very low amount of vram so I had to close all layout tabs before right clicking the layout in the project toolbar and selecting "run layout". Also if you run in debug mode it should show the estimated vram usage in the toolbar.
Moving over to C2 wouldn't give you more vram so you'd probably run into a similar issue.
Now if adding another object at all, no matter it's texture size, causes the runtime error then there is something else amiss, not vram running out.