Doing an SPV node messages over near-vertical incident skywave (NVIS) is technologically feasible, though not 100% reliable. Doing a full node is probably infeasible unless you use Blockstream Satellite or similar for the big messages.
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How about UHF?
It's much shorter range than NVIS, you are much less likely to find another node to talk to. If you find a partner and both locate yourselves on each side of a censored internet gateway you could do full node msgs, but that's a costly thing to do.