When can we expect a new patch for 11.0?

What makes you think that you can get an answer to that?
I have to change some things in dozens of OS. If p11 comes in 1-2 weeks, I wait.
In another case I make my changes and upgrade to 11.1p0 directly.
Without describing of the above story I've just wanted to ask about update or upgrade.
What I do on FreeBSD-Security-Advisories is (world and custom kernels built from source):

1. Reading SAs immediately when got notice.
2. Deciding whether it does affect my configured sytems or not.
3. If an SA affects a system immediate action is taken, else nothing is done.

Ad 2. Let's say there is a SA regarding i.e. ntpd and none of my system use it I do skip it.
If it affects a kernel module that is never used i skip it too.

Also I prefer wherever possible to use ports versions over FreeBSD-base-versions (except SSH). This significantly reduced the events for rebuilding world.

Nevertheless if a SA does affect any of my systems immediate action is taken.
Patches on -RELEASE versions are mostly driven by security issues. And because nobody has a crystal ball to look into the future it will be impossible to say if 11.0-RELEASE-p11 will come before 11.1-RELEASE. It's however unlikely it will come after 11.1-RELEASE because 11.0-RELEASE will be EoL 3 months after the release of 11.1. So instead of patching you'll be advised to upgrade, which you should do any way due to the EoL.