How would I say something like “you’re more than welcome to come if you have time” to a friend?

I want to invite my friend to an event with no expectation that they come since they have work late and it's a last minute invite. In English I'd say something like "I'm going to be at the beach around 5. You're more than welcome to pop in if you want, but don't feel obligated."

The only way I can think of with my current knowledge of Japanese is to say something like 「5時頃ビーチに行くつもりだ。時間だあれば、焦らずに来てみてね」
I suppose I can think of a few other ways to say something like this, but none of them really communicate what I want to say.