Do you know anything about the reliability (e.x. 1000km transmissions between two rural areas are possible 5% of the time/50% of the time/90% of the time), as well as the kind of antenna you'd need for that? It'd be very cool if a portable setup was possible.
If the portable HF thing is something that interests you there's something called Summits on the Air which involves hauling a radio up to nearby mountain tops and try to make as many contacts as possible. Even with tech license VHF and HF CW are still something you can do. Elecraft's KX line are really common for these(I own a KX3[3]) and really incredible pieces of kit. With a radio, ~30ft wire and a tree/pole you can definitely make 800mi+ contacts.
[1] https://en.wikipedia.org/wiki/Near_Vertical_Incidence_Skywav...
You can do a lot of optimization if you're working fixed sites. Directional gain and optimal take off angles for a given path can be targeted with excellent results. HF antennas are large. A simple 40 meter horizontal dipole (good night time antenna) is 20 meters long, and it needs to be raised to some altitude that achieves the 'bounce' you want, usually 20 meters or less. Smaller, much less efficient antennas exist.
I regularly hear East European stations here in London, UK with a random length bit of wire strung off a home made 40m receiver and into a tree though. Noise here is terrible so I have had to use very heavy narrow bandwidth audio and IF filtering.
If you want long distance, be prepared to use very narrow bandwidth i.e. learn CW though (its not that hard although I have trouble copying some of the faster stations).