Here is a list of groups currently bidding (seriously) to hold a NASFiC. For more information about NASFiC bids and how the process works, see the Worldcon website. The process for NASFiC bids is similar to that of Worldcon bids, except that sites are selected one year in advance, and that if there is a NASFiC in the year in which the election is held, members of the NASFiC, not the Worldcon, vote on where to hold the site.
2019 NASFiC Bids
Because the 2019 Worldcon will be outside of North America, the members of the 2018 Worldcon in San Jose will vote to select a site for the 2019 NASFiC.
2020 NASFiC Bids
Should a non-North American site be selected for the 2020 Worldcon, the members of the 2019 NASFiC (not the 2019 Worldcon) will vote to select a site for the 2020 NASFiC.
There are currently no groups bidding to host the 2020 NASFiC that we know of.