'Write every day' is what the creativity books advise. I sure wish I could but sometimes life intervenes. So yesterday was the first time in a month I've worked on my novel.
It's not ideal to have these extended interruptions. Still, your work can survive them and still prosper. Planning helps if you have the luxury of knowing a break is coming. Don't leave your work too wrapped up. I stopped writing in the middle of a scene I was excited about. That's practically a guarantee I will get back to work on it.
Use the break for reflection. There are no absolutes. Could the real villain/hero/love interest be someone other than the person you planned? It was for me. I had an aha moment during that month when I wasn't writing that has my plot recharged.
Realize you've lost some fluidity. It's like not exercising for a month. You've got to start slow. Maybe edit a bit before you start writing and then write for short segments. It won't come as easily for awhile.
Your characters may be shy or cross with you. So give them time to share their secrets. It won't take too long. You are the author and they really need you.