We started with a 38’ gasser and are now in a 45’ DP. I don’t think the size of the current rig limits us any more than the size of the first rig. Once we decided we would need a toad, size didn’t really matter to us any longer.
You listed parking lots under ‘cons’ of a bigger rig. If you pull a toad, that isn’t an issue. And finding sites has not been an issue; we’ve always found a site near where we want to be and use the toad to do the exploring and grocery runs.
You already listed your reasons for wanting a bigger rig. If you want a washer/dryer, there’s probably a minimum length that has that option. Reading up on (lots of) specs of different brands and models should give you an idea of what that length is. (I personally recommend a stackable, separate washer/dryer. Our first coach had a combo and it made laundry woefully slow.)
Surprisingly, our first coach had more basement storage and waste tank capacities than our current rig. But not enough to be a deal-breaker. But you might want to pay attention to those while reading those specs.
Given the option, I would recommend a DP over a gasser. And I don’t think the size matters all that much once you get over 36’ or so. If you’re like us, you’ll fill whatever space you have. I would have a hard time downsizing at this point. You already know what you like in way of a floor plan; let that be one of your bigger deciding factors.
Have fun with this process. Thinking about it so far in advance is smart. This daydreaming part and making a wishlist was quite fun for me and started about two years before we traded up. I made three columns:
‘must have’ items (like king bed with room to walk around while making it)
‘Nice to have’ (like separate washer/dryer)
‘Wish list’ (like power hose and shore cord reels and a bath and a half)
Some of those items don’t impact length, some do. (1.5 baths and walk around king definitely do).
All in all, what we want in a rig as full timers is likely very different than most others.