This doesn't seem to get brought up much, but as far as I can see the US will not be ratifying trade deals with anyone until the president , and the majority of the house and senate are from the same party. It doesn't look too likely that this will happen in the 2020 election, so 2023 would be the next possibility.
I suppose that it depends on the nature of the proposed trade deal. If the trade deal enjoys bipartisan support then there's no reason to presume that it wouldn't be passed.
For example a UK/US trade deal which is in the US' favour but where there is no threat to the GFA from the Brexit process would likely sail through.