Family plan for my suspended number is canceled, how can I avoid canceling my number?...

Port you number to google voice.  You can port to a cell carrier when you come back

Thanks! I did some research and found that theoretically I'm not eligible to use google voice, mostly because right now I'm not in the US anymore: 

Google Voice is intended for use only in the USA, and it requires another, US-based forwarding phone number to be provided to authenticate an account when requesting a Google Voice number, regardless of whether your Google Voice number is issued by Google, or ported in from another carrier.  You also must use a US-based forwarding telephone number to record and manage voicemail greetings.

 

You need to be located within the 48 contiguous US states, and you must be able to receive the verification phone call, in the US, on the forwarding phone.  Google Voice does not forward to non-US phone numbers.  Number ports also require a verification call to be answered in the US.  This is for security and fraud-prevention purposes, and there is no workaround.

 

Google Voice is not suitable for saving or "parking" a US mobile number while abroad.

However, there're still plenty of articles talking about using Googlevoice after moving abroad so I figure as long as I can set up a googlevoice account successfully (using vpn/ asking someone in the US to help), then forwarding everything to Google Hangouts rather than my international number, it should be fine... It just sounds very tricky though: 

 You must have a forwarding phone number on the account in order to record and change/update voicemail greetings, and to serve as an account security measure when accessing messages over the phone.  Yes, you can do most of what you described, but we strongly advise against people parking numbers, intending to port them back again later.  There's just too many headaches and things that go wrong with porting.  You can look right here in the forum and see hundreds of people reporting failed or stuck ports every week.  Furthermore, Google Voice numbers are classified as land lines, and porting in and out of a land line carrier is much more complex, and requires more "paperwork" and takes much longer, than a simple mobile-to-mobile port.   Thi8s is due to the legacy processes from the land line telephone company era, and FCC regulations requiring more due diligence about proof of identifying the customer and documenting their legal approval to port the number.  Finally people who are leaving the country tomorrow want to port in their number, and it's simply impossible in that time frame.  Numbers can't be ported while outside the US.

https://productforums.google.com/forum/#!msg/voice/IlNO-e5dGw0/SRtsjppfEgAJ

Are there any workarounds?

I have another idea which seems painful too: How much will this cost: restore my suspended number - then start the easiest individual plan - then suspend the phone???