Thanks for the quick reply! That's what I thought regarding the 250 limit. None of my individual lists/accounts had anywhere close to 250. I just couldn't figure out why I was having issues migrating... and in going back over the instructions, I started to think well, damn, maybe they meant 250 limit for ALL entries. Good to know that's not the case I guess, but with the deadline looming, I'm still unable to migrate my lists/accounts over, and I can't figure out why...
I just tried to select only my most important accounts/lists (leaving 4 or 5 lists/accounts previously checked, deselected this time) and then clicked "Continue". As with past attempts, the "Migrating!" window pops up and the circular dots continually spin while the window refreshes every couple of seconds, leaving me to believe that the accounts are indeed migrating over. After 5-10 minutes of this, I'm met with an error. I even tried to just migrate one small account. I selected only 1 folder (with just 40 stock entries in it) renamed it and left all other accounts/lists unchecked and clicked "Continue" to initiate the migration, but it failed...
I keep getting one of two errors:
Whoops!
We can't show you this right now. We'll get it fixed soon.
2014-12-22T05:33:27.7342781+00:00
4aec8275-290b-450a-a1d7-ac9f6148742b

or this error:
There was a problem migrating your watchlists. Please try again in few minutes.