The first amendment absolutely can protect from a charge of trespassing, or from any other charge. We don't know if it will in this particular scenario, but speaking categorically? Yes, it can absolutely.

A recent high profile example of trespass law clashing with the first amendment would be free speech zones.

The Constitution constrains the construction and application of all laws. Every single one.

A quick search for "free speech zone court case" only found cases effectively upholding trespass law over free speech. To what court case or law are you referring?

Some starting points here: https://en.wikipedia.org/wiki/Free_speech_zone#Notable_incid...

First amendment entanglements with trespass generally occur on public land where some local authority has prohibited some sort of activity involving speech. There usually aren't first amendment issues to be raised with trespass of private property, as rights are relevant with respect to government authority.

No, it cannot. Trespass is illegal. Trespassing because you want to speak on the property is still illegal.