I paddle a tandem solo with a double paddle as my primary paddle.
I'm using a rental SR16 so lowering the seat isn't an option. If I could I'd lower the seat a few inches.
Trimming your load is paramount solo. I push my heaviest pack forward and the other crossways, keeping both below the gunnels.
If I could I'd take out the stern seat to allow more weight in the bow. For now I use a dry bag filled with water for ballast if it becomes necessary.

No way your tandem will perform speed wise with a dedicated solo,( a double paddle helps here) but there are positive tradeoffs.
Much more stability, easier to load gear in and out of. In shallow water the extra hull volume means you can go shallower than a narrow solo. Depending on water levels that may be a big plus.

IF I owned a tandem, I'd pull the stern seat out when solo to save weight.
I'm sure you could heel it over from a sitting position with a little caution. With the lowered seat, I think it would be just a matter of learning it's limits. You also want to turn the yoke around so you don't have to turn the canoe around on landing.

Another point about trimming your load properly. True solo or not, your better off a tad bow heavy than light, especially if the wind picks up. That extra foot in the 17 makes it even more important you get it trimmed right before you head out into the open water.