How can I use the get_followers function in rtweet package with a unstable internet connection

Question

I am a PhD student and now working on mining twitter data. I need to collect userids for realDonaldTrump's 88M followers. It will take about 15 days but the internet connection in my apartment is not very good, just like this:

7500000 followers!
Waiting about 15 minutes for rate limit reset...
Error in curl::curl_fetch_memory(url, handle = handle) : 
  Could not resolve host: api.twitter.com

and all the 7500000 followers I already downloaded disappear. So could you please give me some suggestions about:

1. saveing the followers before running next round.
2. or make rtweet check the internet connection before making decisions to continue or wait.

Thanks so much. WZ

In fact I'm doing research about polarization so I need to classify every user into categories of republicans or democrats, it depends on how many republican (democrate) accounts the user follows. Because getting followees is very time-consuming, so I have to get all followers of each politicans,and check how many times a user appears in republican/democrate politicans' follower sets, which makes the vector very large. This is the only solution I can think of, even though very stupid. I just use one line of code:

TrumpFollowers<-get_followers("realDonaldTrump",n=90000000,retryonratelimit = TRUE)