The question I would answer first is, are you absolutely certain that a TT of that size (20'-9") and layout is going to work for you? The first TT we bought was the same size and when we bought it we thought it was going to be our forever TT. But it only lasted a year before we discovered it was just way too small and cramped for the two of us. We ended moving up to a longer one with a slide, sofa, walk-in shower and full walk-around bed and we lost a ton of money on selling the old one. This should be more of a consideration for anyone planning to do lots of travelling.
If you perchance do end up finding the TT too small and want to think about something larger, you wouldn't want to find that your new TV isn't enough for a heavier TT. Then you could end up not only losing a bundle of $$ selling your original TT, you could also lose $$ on having to upgrade to a more capable TV. Maybe you could find a CG that has rental TTs to get an idea of what it would be like in a TT the size of the Lance 1685.