Fundamentally, this post is rediculous, but I'll bite.
If you really want to get the most out of your two club lengths from lateral hazards, and only have 13 clubs, carry a second putter. You can make this thing as long as you want, as I believe there is NOT a length restriction on putters. For instance, you could build a broom-handle putter that you hold under your chin. That'll be almost 6 feet, 72".
Going from a 44" to a 47" driver for drops is really only going to gain you 6 inches, half a foot, on 2 club length drops. In unplayable lies, it is only gaining you 3 inches. Not really worth it.
BUT, if you have a Bernhard Langer/Carl Pettersson 72" model, you are gaining 28" over your driver. Times 2, that is 56", or 4' 8". With almost 5 feet extra, a lot of the time you will be dropping in the fairway.
Remember, under the Rules of Golf, most often when taking relief you do NOT need to stay in the "same conditions". i.e. if your ball is in casual water in the rough, you need to stay in the rough. This IS the case for MOST scrambles, but scrambles aren't exactly real golf. In the Rules of Golf, for the most part the rules state, "Nearest point of relief, no closer to the hole, within "X-AMOUNT" of clublengths."
So having a long club for drops isn't just an advantage for hazards. Casual water, sprinkler heads, drainage ditches, cart paths. All of these are complete relief, plus a club length. With a little ingenuity, and an extra 2.5" over your driver, you should be able to find a GREAT place to drop most every time and the other times, you'll be dropping in the fairway.
In so far as the "spirit of the game", only you can answer that. If the USGA felt it was that great of an advantage, they would have limited putters to the artificial 48" maximum of clubs also. They chose not to do that, so you are well within your right, IMO, to take advantage of it.
I love questions like this...
