The other legalistic quibbling aside, there is no expiration date on consideration...all Congress can do is basically watch, if the states together decide the 2/3 threshhold has been met they can convene, and if a resolution is agreed to 3/4ths of the states in convention or in their legislatures then the resolution becomes an Amendment, period.
So seems to me somebody has to poll the states as to the status of their request and it seems to me the best way would be for officials in a Pro state start making calls and have their AG offer an opinion with respect to meeting the 2/3rds hurdle.