Congrats on the Dread Susan.

You will get a bolder and fuller sound due to the bigger body, however as you discovered the disadvantage of playing a dread. They're a lot of instrument to handle. I'm 5-9 with I'd say average size hands and I would probably have a hard time getting used to one cause I play sitting mostly. My Breedlove is a concert and my next acoustic I'll probably go to a mini or parlour. Standing up as you stated is probably the preffered method with something that big.

I don't know any specific exercises other than probably take a few minutes to do some spider leg warmups before jumping into something. I drive trucks for a living and throughout the day I might be in two or three different ones including my own vehicle and I remember my instructor telling me you should always take a minute to get your mind into the vehicle your driving before you take off. Think about the different subtlies, characteristics and size of each one and let your body make it's adjustments. A few warmups and some scales should get your fingers to adjust to the different size neck and fingerboard. You might find you'll need to stretch a bit more on certain chords though.

Your strumming hand might have the bigger adjustments as your shoulder will be a little higher and your arm has to come out more to accomodate the wider body. Looking at the picture though it seems to fit you pretty good so you might be ok. As long as it's not causing any discomfort I'd say your ok but be very conscious of the right shoulder. I have the same problems when I go from my acoustic to my electric and visa versa. It takes a minute for the hands to get used to the neck and body size. Every guitar is different which is a good thing. I get more impressed when I see performers pickup various size guitars during their shows without missing a beat. Check out some of Sheryl Crows concerts. She goes from Fender Telecaster to full size Gibson Hummingbirds with ease and she's a small lady.

It's all part of our learning process I guess. Like we don't have enough to learn right. lol

Enjoy the dread.

Moe