cheapest emergency phone setup?

Ok, I got too enthusiastic playing with big downloads of linux operating systems and software.  Last week january had no phone.  Though RedPocket promises unlimited calls and texts, once you blow through your data and the wee bit throttled data, you are dead in the water.  They just turned off my account.  Wont even go into how once my 360 day plan renewed for February, couldnt use it until I got hold of somebody to reset my account.  This required no less that three trips to library to repeatedly submit a troubleshooting "ticket" on their website.

So yea my fault not paying attention to data and not setting limit on the phone to shut down data after set amount used for the period. Dont use data once its throttled, leave it for the voice and texts or maybe pop3 email.

But got me realizing there are no pay phones anymore so I can be left high and dry if RedPocket on ATT network goes down for whatever reason and i am out here in rural area.  Maybe a minimum Tmoible network account??  Obvious lowest cost option be TextNow.  Free with ads, requires you run their app on your phone.  Requires minimum of Android 7.  You have to buy a $5 SIM for your unlocked GSM phone to run it on Tmobile network.  And you have to use it at least once per month to keep your number.  On positive side, unlike RedPocket you can make wifi calls.  Something I couldnt do at library with phone on wifi using Red Pocket.  They had completely shut off my account.

Now looking at other Tmobile MNVOs and most interesting was Tello.  This lets you create your own plan with varying amounts data and voice.  Think all have unlimited text except the data only plan.  Well the bare minimum is 100minutes voice, unlimited text, and no data is $5 a month.  $60 a year.  For an emergency option, this isnt bad.  But add 2GB data and it only goes up to $7 a month.  $2 for 2GB data is good deal.  They have no problem with tethering or using phone hotspot app.  Think assuming you will then buy more addon data from them.  If you do it right with pop3 email account, this 2GB data could give email all month and data left over.  You would need an OS that doesnt try to autoupdate anything, also apps that dont try to autoupdate. unfortunately short of rooting a phone cant easily stop updates on it.  Maybe one of the Puppies with CLAWS email or such.  Been long time think there are even more basic email clients, though if they support current standards for pop3 unknown.  Maybe Thunderbird can be locked down though it constantly nags to be updated which just makes me NOT want to let it update. Seriously developers need to stop making their apps obnoxious about updates. Ask politely ONCE, then drop it.  And pop3 set to limit size of emails downloaded and only text dont download images or attachments.  Pop3 is one of remaining ways to get by with minimal data and still communicate with the world. About the only useful way to use dialup anymore, though cant imagine why anybody would even consider dialup if they have a cell signal.  Just about all websites try to force eye candy and ads and want to use your data for tracking apps and such.  You can block lot of that, but it still sucks data.  No way to block it all.  Hmm suppose could use FairEmail on the phone itself....  Its modern and should work.  Need to use it through scrcpy so have big screen and real keyboard. Trying to email on a phone would be unpleasant.

Am currently thinking this minimalist Tello plan make good backup and no requirement I use it, just fork over the money.  So woudnt lose my number if I forget to make a call or text during the month.  Tello makes it easy to cancel online.  So no being tied into things with activation fees or cancellation fees or multi month plans or customer service people that put you on hold forever and speak with heavy accents.  No I am not recommending Tello yet, havent actually used it, but so far I like their business model and website, more so than others I looked at with lot more gotchas involved.  

Anyway interesting thought exercise on how to be online without spending much money.  Obviously TextNow is cheapest, but with lot gotchas.  Be good for kid that wants to text his friends using cell connection without spending any money.  Actually this would be great for a kid wanting a cell phone but cant afford a cell plan.  I just dont think maybe most reliable as an emergency phone service.  Plus to use it you gotta use their app on your phone and watch ads before texting or phoning.  Well unless you subscribe for $40 a year, that eliminates ads though you still have to use their app.

Hmm, looking at email clients. Alpine be good choice maybe. Modern but text based, runs in a terminal. So text only, not going to download any images. But Sylpheed/Claws or Fairmail be ok I am sure. hmm, Fairmail probably work fine via Waydroid.