As you know, I play mainly alto, but over the last couple of days I've dragged the old tenor out again. I tend not to play it very much due to my strange practising habits, and last time I was playing it, a couple of eeks back, I was sounding profoundly terrible and got a bit despondent about playing tenor altogether, to the point where I was seriously thinking about selling it to fund a companion alto to my YAS62.
However, over the last couple of days I've gone back from the Jumbo Java Mpc to the Selmer Soloist C*, and...... I can play tenor again! And I love it! I know what mfox means about needing more stamina for the tenor, and if you haven't played tenor for a while, or played one before, the lowest notes can take a little work to get them sounding properly, but once you're there it's not hard to go backwards, if you like, and get the horn sounding good at very low volume, as well as good and loud.
I think maybe I need a mouthpiece somewhere between my Selmer C* and the Vandoren Jumbo Java (somewhat more raucous, big, maybe too big, opening, bought as a cheaper alternative to a metal piece), and as I like the Selmers, perhaps an E-ish might do the job.
In short, though, I reckon if you play alto you can play tenor with some not too extreme adjustment. For playing standing up, it's probably the most relaxed in terms of your stance.
Cheers, Bob