futures 0.3 has a compat feature, which enables a bunch of "futures 0.1" <-> "futures 0.3" combinators. I've used it successfully for some projects before. However, I don't know how robust it general, especially if the other project depends on a specific executor, like tokio 0.1 - doing this might end up with errors about not being in an executor context, or it might end up with just running both the tokio 0.1 and tokio 0.2 executors.
There's a blog post which explains more of the compat layer, and gives a short demonstration here: Compatibility Layer | Futures-rs