Mini-Rectifier Tube Life/Back up Tubes

Bought a new Mini-Rect last month. Love it, love it, love it. Since I co-own and operate a studio with clients and deadlines, I try to keep backup gear at the ready...Murphy's Law. I'm not experiencing any issues and don't expect to have issues any time soon, I am curious how long other Mini users go before I having to replace a tube. Please keep in mind that I'm 100% a studio guy; I haven't played on stage in over 20 years. However, I do fire up my Mini (of late) everyday either to practice, write or record on a project for at least 2 hours. I also have an Orange Micro Dark and a couple of Synergy modules too, so if I had a deadline and had to switch amps under a deadline or in a session, I have that option. (I actually had an issue last year in which I had to record a clean guitar part for a podcast and could not use my Synergy T/DXL, so I used the Orange).

So my question is -- when can I reasonably expect to have a tube issue with the Mini...2-3 years from now? 5 years? 10? One of my tube workhorses is the Avalon Sp-737 mic-pre/channel strip. I've used it virtually every day for tracking vocals, bass, DI guitar and/or mixing since 2013 and I haven't had a tube (or any) issue yet. However, I have a full 4-matched tubes kit at the ready in the event of a tube failure. My other high voltage, high use tube studio piece is the Manley Massive Passive EQ that I've had since 2015. Again no issues.

Thanks to all in advance.

Congrats on your purchase, I have the Mini Rec also. In all seriousness, you should be able to expect the same tube lifespan as you would any other amplifier. It all depends on how long and loud you play it each day. All you can do is try to run it at a reasonable volume and make sure to put it on standby any time there are significant gaps in your playing but still need to keep powered up. I would recommend trying to get a set of backup tubes as soon as you can regardless. Good luck, hope the tubes last a long time for you.