Remember that your last place of residence in the US determines your voting residence while living abroad. If possible, move to a swing state (preferably with low population, and preferably in a swing district for local elections, too) long enough to establish residency before moving abroad. Plan ahead now and maximize the impact of your vote in the long run. Also register as a republican so you can vote in republican primaries (to vote for anyone who isn’t Trump), as well as making gerrymandering harder.