Chad Johnson.
Vaguely more seriously? Try to ship Allen to Philadelphia for Brian Elliott.
More seriously? Deal Allen to Columbus, try to get Mike Condon from Tampa. Columbus gets a more proven goalie than what they've got [which isn't saying much, but they're seriously scraping it right now], Tampa unloads a contract that will eat up about $1.5 million in the minors so they get cap flexibility, we open up $1.95 million in cap space and get someone at least serviceable and who's UFA at season's end when we can go look for a better backup.
Not saying Condon is a perfect replacement, but for what this team needs and to give us flexibility we could do a hell of a lot worse. Like, ... well, up above.
Mike Condon played 3 professional hockey games last year. He posted an .800 in 2 NHL starts and a .739 in his single AHL start. That was a total of 14 goals allowed in 135 minutes. He has had one NHL season where his SV% was higher than Jake Allen's career worst. He was sidelined most of last season due to hip issues on the same hip he has already had surgically repaired. A cortisone injection didn't do anything and then he finally underwent an experimental stem cell treatment to fix the issue. He hasn't played a game since the treatment. That is far from a serviceable option, is almost certainly a huge downgrade from Jake Allen, only saves us $1.9 mil in cap space this year and is a huge injury risk. Hard, hard pass.
I'm not sure why Philly would trade Elliott for Allen. Elliott is by all accounts a good pro and mentor for Carter Hart, he is a known quantity within the Flyers organization and they just signed him less than 2 months ago. This isn't an EA game, that's just not going to happen.
Edit: there are 5 current UFA goalies who played 1 or more NHL games this year. Ward, Johnson, McKenna, Darling, and Neuvirth. Darling and Neuvirth played fewer than 10 games and none of those guys hit the .900 SV% mark.
Our cap structure is fine next season and Allen's floor is that of an adequate backup. In his role as Binny's backup last year, he was among the best 5 backups in the league. Assuming that is not sustainable, his overall SV% still put him in the middle of the pack among backups. I think he will probably be a .910-.915 guy in a 30ish start workload that is road heavy, which is much better than any realistic replacement options.
Barring a huge, unexpected turn of events, he needs to go next summer. But he will be easier to move with just one year left on his deal than he is now and we'll have a better idea whether Husso is ready to backup and exactly what we have in Binny.