You can do this by enabling the compat tree in FreeIPA. I believe this will involve you
having to run ipa-adtrust-install --enable-compat on all IPA servers that are involved
either being a trust controller or trust agent. You'll essentially have these trees
after that you can use:
What will happen is all IPA users and groups will show up immediately, but the AD
users/groups won't until they are asked for (eg from a simple ldapsearch or
otherwise), which should (hopefully) be sufficient. In my previous cases of having to use
the compat tree, it was for legacy clients (eg BSD, Solaris/OmniOS/Illumos, and RHEL 5).