I have done extensive HFTA simulation with the state of art simulation software included our specific antenna setup. Based on this operators in US should expect our signals in range S6 to S9 on e.g 20m. Stations in midwest will have slightly lower signals than east and west coast. I have done a comparison where I put our station at NW (Nyrøysa) and compared it to our actual SE QTH at Cape Fie, and it shows an attenuation of only 6 db. I did the same comparison for JA stations with one simulation from NW QTH and compared it with SE QTH. A NW QTH for JA (and east EU stations) is shown in the simulations as a total blocking of the signals. It means that the Cape Fie QTH is a very good overall QTH also given the fact that this is the only safe place to stay overnight on Bouvet.
Our antenna setup has been adapted to the US in a way that we have made sure to improve the signals in your direction. Our setup include two yagis locked towards US (one tribandet and one warc bander), in addition we have an option to rotate two more yagis 90 degrees to US, so at max we will have 4 yagis pointing to US. All these yagis come with a 4O3A combiner and filters so we can run three stations simultaneously on each tribander and two stations on each dualbander.
For signal strenght I want to emphasize that if you run low power into a vertical you belong to the group that would benefit of improving your setup. If you belong to that group you still have time to work on your antenna setup so to increase your chances. Pick a band or two, improve your antenna, make sure you are on the air, and this will be a success for you.