Yeah, 2TB 2230 drives are still a bit pricey but definitely an option.
I think the more cost effective way is getting a bigger microSD card, and using that in conjunction with the SSD. Games installed on the SD card run great and I haven't had any issues with this at all.
I would imagine so as it seems they aren't dependent on heavy writes. The lack of DRAM on the smaller SSDs too, causes issues in cases where write activity is heavy.